Still Life - Almost all of these say what they are outright. Garden Decorations, just use those flamingos from buy mode. Objects will come up at some point there's not any method to it really. The only hard one is Nectar and Food. I got it by placing one single portion of Autumn Salad at a place on a dining table, putting one full bottle of nectar next to it and pouring one glass of another nectar bottle and putting that next to it also. It doesn't work if you put a tray of nectar glasses down - it has to be one glass.
Family & Friends - My Spouse, Family Member, Three of my Friends, Housemate, My Child, My Friend, Two of my Friends, and My Grandchild are all self-explanatory. Ghostly Family is a family member who happens to be a ghost, and My Main Squeeze is your girlfriend or spouse. Be sure that your photographer doesn't have a ghost spouse, because if they do My Spouse and My Main Squeeze are lost causes.
Everyday Moments - A Sim Gardening, Sim using a Computer, Someone Painting, Police Officer, Chessmatch, Mail Carrier, 4 Sims Eating, Kid playing with Toybox, Kid playing with Oven, A Sim Cooking, and A Sim Fishing are all self explanatory. Get more sims into your household to help you with these photos. Child Being Carried requires you to have a child and another adult to carry said child, plus it can be kind of tricky to get. A Sim in the Area, Two's Company, Three's a Crowd, and A Group of Sims all require certain amounts of sims. They should be easy when you walk around town. Try visiting bars. Make sure that none of your subjects are vampires or the photo won't work. Remedy for a Hot Day is sims getting drinks from juice bars. Lovers at Night is two sims kissing at night, generally outdoors. For Pizza Delivery, try photographing the guy himself. Maid at Work and Repairman on the Job require you to hire service people and watch their work. Babysitter is like this too, but you need a child in the home to do it. Firefighter can be acquired at the fire station with ambitions, otherwise just call one and live with the fine. Political Demonstration can be hard to get without UL, but with UL you can just stage a rebel protest. Photo of Photographer is hard. Pause the game and then have both sims take a photo. Then choose the one intended for the photo and unpause the game and then pause the game again and take the photo.
Home Sweet Home - All pretty easy. There are two home decor, I tried using an ambitions sculpture for the second one and that worked once but in this particular file I got it somehow and I don't even know how. Furniture will come up randomly but don't worry about it. Baby Stuff = a crib, Toys and Hobbies = two easels, Something Yummy = a plate of food, Gadgets Galore = a video game thingie, Cute Teddy Bear doesn't need explaining, neither does A Toilet, Kitchen Kitcsh = a coffee maker, A Party = balloons, Bathroom Stuff = toilet and hand towel or toilet paper and towels. Outdoor stuff is anything from the outdoor tab. A Nice Garden is next to impossible. Do it in either spring or summer, else it will not work. Then just swing the camera around and hope for the best.
Around Town - Simple and self-explanatory. Again Sunset Valley would be best for this but I'm nuts so I did it in Moonlight Falls. Only hard one is Police Car - good luck with that, but you can always just have someone do law enforcement career. I just happened to get lucky with it but I might've had to do that in the end. The Diner only works on the default base-game diner.
Travel - A Pyramid, Abu Simbel, The Great Sphinx, and the Torch of Anubis are all in Egypt. Dragon Cave is in China. Piles of Ancient Coins, Relics, Pushable Statues, Piles of Rubble, Floor Traps, Sarcophagi, Treasure Chests, Giant Boulders, and Floor Switches. Shower in a Can doesn't work if someone uses it, just put it down. Snake Charmer - you can purchase the baskets in Egypt, then just have a sim use it. Lovers in Egypt, Lovers in France, and Lovers in China are all just people flirting with each other in these locations. If it goes beyond that it becomes Get a Room. The soulpeace statue is found within the Sphinx, which is only accessible if you're cursed by the mummy or able to use tranquil transference or Zeneport from martial arts.
Oh, the Calamity! - One Sick Sim can be acquired by drinking Ad Nauseum. Soaked to the Bone is easy with Seasons but otherwise you will need a dive well in another town. A Social Worker - I would adopt a pet and wait for it to come. A Fight requires sims actually fighting. Make sure they are not friends of yours or it will be Two of My Friends. Slap Fights is similar. The Repoman requires you to forget a bill. A Thief - you need an actual theif to come by. Lots of luck involved. A Singed Sim - use the chemistry table from Gen until you get singed, then take a photo. Oh No, Snake! is a sim snake charming with a King Cobra.
Collectables - Just put these on the ground to photograph. Mercury Vial is just smelted mercury. Gold, Silver, Copper, Mummitorium (from WA destinations) and Iron should not be smelted. The gems - Opal, Geode, Tiberium, Quartz, Luminorous Gem, White Diamond, Pink Diamond, Rainbow Gem, and Topaz - shouldn't be cut when they are photographed. Space Rock is obvious. China Statue Set, Egyptian Statue Set, Dangerous Creatures Statue Set, Dropa Stone Set, and Canopic Jar Set will all take time to collect. Check the guide for information on how to get those sets. Magic Gnome - check the wiki page here -
http://sims.wikia.com/wiki/Gnomes - and find out how to get them.
Architectural & Buildings - General Hospital, Bookstore, Mausoleum, Sports Stadium, City Hall, and Town Theatre can all be acquired at home. Academy, The Market, and Chinese Garden are in China. French Market and Nectary are in France. Just head to the location and grab a picture. If you have Late Night installed, you have one shot to get a picture of the Nectary before it becomes a permanent Hotspot instead: go to France for the first time ever in your file, and get a shot of the Nectary before 5PM that day.
Paranormal - Resurrect 5 ghosts and get one human housemate for this. A Ghost is 1 ghost, A Ghostly Problem is 2 ghosts, Too Many Ghosts is 3 ghosts, and A Serious Ghost Problem is 5 ghosts. Make a cursed sarcophagus of the kings using the Evil trait, then create a mummy for A Mummy and Mummy Having a Snack. Kill the mummy (with fire) for Doubly Dead. My Dead Spouse and My Dead Enemy are both just ghostly versions of what they are. Wandering Ghost is just a ghost moving, and It's Haunted is a ghost haunting something. Death on Vacation will be hard, but you can always just drown one of your controlled sims in a pool. Simply Death is the Grim Reaper. A lot of the ghost photos for the Paranormal collection can be achieved at the Graveyard using the firework-setting-off-trick.
Best in Class - It has to be THE MOST expensive version of Expensive Stereo, Luxury Car, Fancy Tent, and Nectar Rack. The most expensive stereo can be found at the elixir consignment store. The Nectar Rack has to be completely empty of nectar for it to register. Garden to get the Money Tree. Omniplant is at the science center. A Limo can be acquired by being a 5 star celebrity or a high level business person. You get them at the later stages of the Showtime professions too (a quick way to get one of those is to find a homeless sim employed in a Showtime profession; often they're at the top or close). You could also try to catch it if you have a teen going to prom.
All of these people are at level 8 or higher of their career. Superstar is musical superstar, Supercop is law enforcement, A Top Chef is culinary, Chief Lifesaver is medical, Military Bigwig is military, Diplomat Extraordinaire is political, and Master Criminal is criminal.
Plants and Flowers - White Roses are called 'Semi Roses' in BuildMode and can be found under the Flowers tab. You can also find sunflowers there, but choose the sunflower with multiple heads and when you take the picture make sure the top head is facing you. Red Roses are the Rosey Roses. Hydrangea is also in there. The rest are fairly self explanatory, place the allowed lots in your file and you can get the WA plants easily. The produce carts are also BRILLIANT for this.
Sims in Motion Collection - You need a few housemates for these photos. Making Nectar, Running, Sim Making the Bed, Playing Catch, Sims Sparring, Fighting a Fire, Refreshing Swim, Board Breaker, Solo Dancer, and Sims Dancing (2 or more) are all easy. Pleading to Sphinx and Pushing Statue will be pretty easy, but you need to travel with another sim. Honing Body and Mind is a sim meditating or snake charming. Get a Room! is sims making out or further than that. Fighting Flab is a sim exercising. Dumpster Diving is a sim digging in a trash can. You can only do this if the home where the trash can is located is occupied. Great Tunes is a sim playing music.
Ambitions - You will need an inventor, a sculptor/stylist, and a child sim for this collection. Sculpture Garden is 5 or more sim-made sculptures (topiaries work the best), and Eccentric Collection is 5 or more inventions. Get your housemate on a trampoline and take a picture for Big Air. For A Makeover - get a stylist in the family, send them to the styling station with your photographer, pause, que up a makeover on one person and a photo for the photographer, then press play. It should work! It is similar for Getting a Tattoo, just use a tattoo machine instead. Get a photo of your level 8 stylist (or architect, or PI) for Top Brass. Have the kid sell baked goods with the baking table for Bake Sale. Have your inventor detonate something for Fire in the Hole. Send your sim to the Fire Station for a Fire Engine, then take a photo of the inventing bench there for Tools of the Trade. Tools of the Trade also works with sculpting stations, styling stations, drafting tables, etc.
Nightlife - You need one helper for this, and need to be in Bridgeport. Head to a Hotspot bar for A Hotspot, then go to the bar there for A Mixologist. Send your helper to play on the dart board for Bar Games, then have them drink a bit for Cocktails and start dancing on the table for Dancing Fools. (Bar games can sometimes work without the helper playing on the dartboard, just take a photo of the dartboard.) Celebrity Sighting needs a four star celebrity, and Vampire needs a vamp. Hopefully both will be at the bar, but if they aren't look around town. After all this, head home. Rocking out is your helper playing an instrument. Then get a small pool and have your helper skinny dip with a lover for SkinnyDipping.
Generations - You need a kid (you can always adopt a toddler) for these photos. Have the toddler play with their IF for Imaginary Friend, then age the kid up. Caught! is that kid pulling a prank and being seen. Have your kid throw a slumber party for Sleepover Fun, then have them play catch with a guest for Backyard Fun and pillow fight with a guest for Pillow Fighting.
Let the kid age up to YA, and then take a photo of Graduation. Get them engaged, then throw a bachelor party for Party Sims and Party Dancers. Have them try the chemistry bench to get For Science! A Wedding can be just a wedding arch.
Animal Kingdom - Buy a bird to get Pet in a Cage and Birdie. Then adopt one pet of each type, take photos for a Dog, A Cat, A Horse. Make at least two of those adopted animals babies for Baby Animals. Then take a photo of them all together for A Zoo. Then have another sim ride the horse for Horse and Rider. My Pet will fall somewhere in here, the only hard photo in this collection is a Deer so use that stray animal gnome to attract them and hope for the best.
Pets in Action - You need a rider, a cat, a dog, and an elderly horse for this collection. Cute Cat is a cat playing with a toy, and Clever Cat is a cat hunting something. Dog Tricks is a dog doing a trick and Tug of War is a dog playing tugofwar with a human. Teach a bird at least one language for Talking Bird, then wait until it dies for Dead Bird. Death Riding - when a horse dies, Death comes for the horse soul and rides the horse. Adopt an elderly horse. Have them do jumps for Show Jumping and perform the heroic pose action with a rider for Heroic Horse. Then let them die. Pet Cemetery is a pet grave, so once your horse is dead that will be easy.
Supernatural - You need one witch helper (in the fortune teller career) for this, one werewolf, one fairy, and you need to be in Moonlight Falls. Fortune Teller is a sim at level six of that career. Mystic architecture is the mystical place next to the moonlight falls library. ZOMBIES! is self-explanatory, just wait for a full moon and there you go. You can find Magic Mushrooms near the elixir store. They need to be harvestable. Have the helper buy an elixir at the consignment store, the put it on the ground for Elixir. Your witch helper should then duel with a Crumplebottom sister for Spellcasting Duel, and your werewolf helper should play fetch with them for Werewolf Playing Fetch. Then make the werewolf howl for Howling Werewolf, and scratch furniture for Werewolf Scratching Furniture. Fairy Trick is pretty easy if you have a fairy. Magical Items is the bubblegum machine-ish thing.
Seasons - You only need one helper for this. Rainy Day is an unknown sim with an umbrella. Aliens! can be attracted with lots of space rocks. Alien ships can also be parked on community lots (with rabbit holes) and will give you Aliens! as well. Horseshoes can be bought at home, and then play with them for A Game of Horseshoes. Wait until fall to get Autumn Leaves (they're everywhere) and Haunted House, which is at the fair. You can also get A Festival then. In winter, Snow Day! is a sim making a snow angel and Snowball Fight! is self-explanatory. In spring, Spring Dance King and Queen are both sims dancing at the spring festival. In summer, Fun in the Sun is a sim on a floaty in the water (head to the ocean), Serious Competitive Eating is a sim who has challenged another sim to an eating competition at the fair, and Water Balloon Fight! is self-explanatory. During any one of these seasons, throw a feast party or any other kind of party for Seasonal Party.
There is also some good info here:
http://sims.wikia.com/wiki/Photography/Photo_collectionsFor Shutternut, I would recommend Around Town, Home Sweet Home, Animal Kingdom, Still Life and Plants & Flowers. Generations, Seasons, and Architectural Eye all work as well.
Edited multiple times for corrections and additions.