I haven't done too much photography, but I have at some point completed most of the collections so I have some tips about where things are (may or may not be helpful). I've tried to include everything that people have mentioned:
- If you're in SV visit Gobias Koffi's house and go to his garden. He's got all sorts of plants there, including sunflowers (if you aim it right) and several fruit / vegetable plants. The Science Facility, Crystal Springs (correct name?), Stony Falls and the little lake thing with a bridge near the Landgraab and Alto households also have fruit / vegetable plants, some of them rare. The Twinbrook Community Gardens can also be helpful
- The white roses are called 'Semi Roses' in BuyMode 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. It might just be my temperamental camera but it only worked for me under those conditions.
- I got Home Decor by photographing a candle only, but the tissue box also works. The coffee machine got me Kitchen Kitsch, the toilet with toilet roll got me Bathroom Stuff, a video game console got me Gadgets Galore. I think the key is making sure that whatever you are photographing is well away from anything else. I tend to do it in a big open space in the garden.
- Remedy for a Hot Day - for me this was a Sim drinking a drink from the bar. I don't think it matters which type of drink, but Quick Drink or something similar might be better than a drink giving specific side effects.
- 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. Sometimes this also works with just a bottle or just a glass. It took forever so this one needs patience
- Shower in a Can - I get that just by placing one on the ground and taking a picture from above. It doesn't register for me if I try to take a picture when another sim is using shower in a can. Maybe that's another case of making sure that everything else is moved away?
- Town Theatre (and any other specific town location) - it has to be a really close-up shot, so close that the location fills the entire lens. I've found that it also has to be at such an angle that the camera isn't facing anything else that's behind the location - so if I'm taking a picture of the theatre and the police station is directly behind the theatre and the lens is facing that way, sometimes it comes up as 'Police Station'. I don't know why, but try to get it so that there's nothing behind the location either.
- Lovers in China - I got this by photographing two locals (Shang Simla residents) who were a married couple and were doing flirty interactions. Not making out or anything, just hold hands and stuff like that. They were in their bedroom and it was at night (creepy much, especially since my Sim was standing there for about three hours taking photos.) I think it becomes 'Get a Room' or something when it gets beyond flirting.
- Wandering Ghost (if that's what it's called) - I actually managed to get this once by fluke. The ghost was doing that thing where it kind of floats along like a zombie, not bobbing up and down or anything. I was lucky because I managed to get it centred - it actually floated straight through another shot I was aiming for. It also wasn't in the graveyard - it was actually floating the streets of Al Simhara. Maybe it has to be moving in that specific way and be away from the graveyard for it to count as a 'wandering' ghost.
- Doubly Dead (a mummy died of old age) - I cheated and did trigger age transition with testingcheats enabled. For any mummy shot, it's easier to aim if the mummy isn't chasing you. Get it so the mummy is released, then use testingcheats teleport or the martial arts zen thing to get to a place where you can still see the mummy, but where the mummy is trapped and can't reach you. They'll just be wandering aimlessly and will be pretty slow also, so it's easier to aim.
- For the gems - I don't know if it's just me, but my camera registered the gems more consistently when they were in rock form i.e. before they were cut. Maybe because they tend to be bigger in that form? For collections, they've got to be close together - I find putting them just on the floor and taking a picture from above is the best way to get it to register.
- Best in Class - this is one of only a few collections I have never been able to fully complete, probably because all my Sims are poor
For me at least, it has to be THE MOST expensive version of whatever object it is, not just AN expensive version. I think one of the objects for Best in Class is a nectar rack? - this has to be completely empty of nectar for it to register.
Sorry about the long post, I hope this helps people who are stuck