I've never got very far into a Legacy... what are your tips for making a successful Legacy?

For example, on another thread I just read someone always tries to get a sim to reach the top of the culinary career because of the fridge they receive as a reward that stops food from spoiling.

Make everything random. Roll the dice when selecting traits rather than picking them yourself. I tend to always take the same ones if I choose. But I don't get quite so bored if I am playing a Sim with traits, career, favorites, etc that are outside of the normal. Take the first career or profession available instead of looking through what's available, or choose to have each Sim have a different job than any before him. Learning new stuff about the game keeps the boredom away.