Now that we have seasons, I've figured out a way to hand out traits based on the time of the year. I've also assigned an animal to each 2 weeks of each season: Penguin, early spring; Llama, late spring; Dog, early summer; Womrat, late summer; Cat, early autumn; Raccoon, late autumn; Freezer Bunny, early winter; Bear, late winter.
Zodiac method
Week 1 of Spring -- angelic (toddler), cheerful (child), family-oriented, good, neat
Week 2 of Spring -- angelic (t), cheerful (c), family-oriented, art lover, glutton
Week 3 of Spring -- charmer (t), creative (c), family-oriented, romantic, dance machine
Week 4 of Spring -- charmer (t), creative (c), family-oriented, outgoing, insider
Week 1 of Summer -- clingy (t), gloomy (c), music-lover, dog lover, evil
Week 2 of Summer -- clingy (t), gloomy (c), music-lover, jealous, materialistic
Week 3 of Summer -- fussy (t), hot-headed (c), music-lover, hates children, squeamish
Week 4 of Summer -- fussy (t), hot-headed (c), music-lover, ambitious, snob
Week 1 of Fall -- independent (t), self-assured (c), loves outdoors, cat lover, loner
Week 2 of Fall -- independent (t), self-assured (c), loves outdoors, non-committal, unflirty
Week 3 of Fall -- inquisitive (t), genius (c), loves outdoors, lazy, perfectionist
Week 4 of Fall -- inquisitive (t), genius (c), loves outdoors, geek, vegetarian
Week 1 of Winter -- silly (t), goofball (c), bookworm, childish, foodie
Week 2 of Winter -- silly (t), goofball (c), bookworm, clumsy, erratic
Week 3 of Winter -- silly (t), goofball (c), bookworm, bro, kleptomaniac
Week 4 of Winter -- silly (t), goofball (c), bookworm, mean, slob
Teen and YA traits should be chosen from the last 3 for each week. You can either assign all the traits when the Sim is born, or assign them when they age up. For example, an infant that becomes a toddler during the 2nd week of Spring would be angelic; when it becomes a child during the 1st week of Fall, it would be self-assured; when it becomes a teen during the 3rd week of Summer, it could be squeamish; and when it becomes a YA during the 2nd week of Winter, it could be a bookworm.
