Here's a mockup of what I'm suggesting. Add three categories to character selection called 'Likes', 'Dislikes', and 'Quirks'. Each category can have 2-4 short entries chosen off a pre-made list, and is intended to provide a quick prompt for fleshing out your character. No entries should have gameplay effects - it's pure fluff. Lists would be composed of jobs (ex. Captain), items (ex. toolbelt), habits (ex. stutters), personality traits (ex. paranoid), colours (ex. red) and species (ex. unathi). There should be significant overlap between lists, such that one character would like or dislike another's likes/dislikes/quirks.
Edit: You could add another category for 'Motives', stuff like wealth, power, justice, cruelty, loyalty, duty, and Honk!