Sorry about the delay in posting strategy, had a bit of real life stuff today. Lots of these already covered by thekatie0409, with some of my own added stuff.
Tip #1 -- Writer Career
You need at least writer career level 3 to be able to get the speed boost in writing books. Level 1 and 2 won't work. 2 hours to write a book vs the normal 4 hours to write a book, that is the biggest tip/strategy I can offer anyone.
Tip #2 -- Connections Reward
So you need at least career level 3. Get connections as soon as you can so you join writer career at level 4 with the writing speed boost.
Tip #3 -- Professional Slacker Reward
You want the writing speed but don't want to waste time going to work. Yet you don't want to get fired from work (for missing work all the time). Use your 3 vacation days, then buy this reward so you don't have to worry about getting fired.
Tip #4 -- Very Inspired
Need to constantly stay in very inspired mood to write your books. I have outdoors (+2), environment (+2), inspired (+2), cloudgaze (+1), loner (+1), and I can always view inspired art to get another +2 if needed.
Tip #5 -- Don't waste time
Again, all about efficiency. Ask yourself what can you do to save time. Do you let your sim walk to the bathroom? Do you let your sim wander around? Control your sim at all time and never let him/her do stuff by themselves. Move the bathroom next to your sim if he/she needs to pee. Move the bed next to your sim if he/she needs to sleep. Only take a few steps around your lot to complete your task when possible.
Tip #6 -- Loner Trait
Well I did mention don't waste time right? If you have loner trait, you never have to worry about socializing. My socialize bar was constantly in the max red, no worries.
Tip #7 -- Cooking
Yes, you read it right. This is a writing challenge but cooking was super important for me. I spend the first day (Sunday) doing nothing but cook, use all the cooking whims I can get to get points. Sunday 11:30am I had 1000 points, bought speed reader. Read faster and gain fun level faster, what's not to like about this reward? By next day Monday 9:00am I had another 3000 points, bought Connections. This is when I stop cooking. I joined writer career and start to get my first level in writing. So from Sunday to Monday 9am, I cook, no writing.
Tip #8 -- Prose and Pop
Before you level writing, make sure you level mixology to level 2 so you can make prose and pop. Drink one of these before writing, you will gain writing skill levels faster. Don't remember exactly how much faster, I think is 50% faster.
Tip #9 -- Future Cube
This is mainly for getting the "SAD" emotion to write your sad book. After I write the children book, I had many positive emotions. I went to sleep waiting for some of the positive emotions to fall off. I wait until I have only +5 happy (2 from environment 2 from outdoors and 1 from loner). I built a small square room and went inside, this will get rid of the +2 from environment and +2 from outdoors, leaving only +1 happy from loner trait. Use the future cube and ask about love life - if results is negative, you will get sad moodlet buff. Quickly click on the computer to start writing a sad book -- when your sim walks out of that room into the next room to write sad book, even if your mood change to happy or inspired, you can still write the sad book as long as you already have the action queue up. If the future cube is successful, you will get romantic moodlet. Don't worry, use the cube and ask scientific (or something else) to get rid of the romantic, then use the cube again to ask love life. Keep repeating until you get sad.
Tip #10 -- Write one genre
Not sure if this one helps, but I think it does. After finishing writing all the genres, I wrote mainly mystery books. Well I did write some other genres to get whim points earlier, but after 2nd week when I don't really need whim points anymore, I only write mystery books.
Tip #11 -- Good Bed & Computer
I bought the most expensive single bed on the first day with my starting money. The one that give you +10 energy, I think it's called Princess Cordelia something. Didn't have enough money to buy the $10,000 computer, so I use the cheapest computer at first - when it breaks, I will call for repair and read book while I wait for repair. After I get some money from royalties and have enough, immediately buy the $10,000 computer. That one is unbreakable, so I never have to worry about breaking it. I like to queue up writing book action for my sim and run on super fast speed. Sometimes if it breaks, my sim will waste time waving her hands and wandering around if I don't catch her and stop her immediately.
Reward Traits Summary:
Speed Reader (Week 1 Sunday 11:30am)
Connections (Week 1 Monday 9:00am)
Never Weary (Week 1 Wednesday 2:00pm)
Creative Visionary (Week 1 Thursday 7:00am)
ASPIRATION COMPLETE (Week 2 Sunday 10:00am)
Professional Slacker (Week 2 Sunday 10:00am)
Steel Bladder (Week 2 Monday 10:00am)
Hardly Hungry (Week 2 Thursday 4:00pm)
Frugal (Week 3 Sunday 9:00pm)
Antiseptic (Week 3 Tuesday 6:30pm)
Marketable / Free Services / Speed Cleaner (Week 4) -- These are not too important.
Marketable only affect the last day when you can't send your books out for royalties, instead you have to sell your books via inventory.
Free Services was for my sim since she broke her shower and needed repair. Don't repair yourself, hire repair service. If you have the free service reward, it is free. If you don't, the repairman will only charge your around $105 for repair.
Speed Cleaner was for my shower also, since it was dirty and gave me negative moodlet. I had extra whim points so why not, bought that and clean the shower quick.