I chose the Professional Author LTW and Artistic, Bookworm, Computer Whiz, Couch Potato and Hates the Outdoors for traits. Artistic was probably the least useful of the bunch - it's supposed to make her learn writing faster, but I don't think it provided me any useful wishes. Bookworm won most useful, of course, just for the "Read x books total" wishes, but Computer Whiz was also really helpful. It boosts the rate at which she gains fun from playing computer games, and Lucy could go from Stressed to Having a Blast in roughly an hour, without even having to move.
I'm a terrible builder, so I just bought her the cheapest house in Riverview and sold off all the appliances so she would wish for them. I ended up not getting her a fridge or stove; I just made do with a mini-fridge. I didn't get a moodlet from the food, but cooking just takes too much time. For decor, I completely abused the vase that comes with the WA registration pack - it's +5 decor and only costs $1. I just stuck two in pretty much every room, and she had a +45 Beautifully Decorated moodlet all the time. Her desk is a little odd looking - she's got a super-cheap desk and the most comfortable chair in the game. Add in a stereo to play her favorite music, and she was in such a good mood that even being Stressed didn't make much of a dent.
My strategy for completing her LTW was heavily influenced by University. I had Lucy specialize in sports books - perhaps slightly ironic, given that she was a Couch Potato, but they're super-short, you only need Writing 3 for them, and they make a ton of money. She could crank out a book and a half to two books in a day. I also had her buy a copy of every single comic book in the bookstore, as they're really short and really cheap. Then whenever she popped a wish to read so many books, I had her read the comic books.