I often use a d4 to determine how many years in they are in that current term, then it becomes edition/char gen specific.
If pure Classic, the number of years = chance of getting 1 (or 2 for non-ranked careers) x25 (i.e., 1st year, 25%, 2nd 50%, 3rd 75%, 4th 100%)
if the extended class (books 4/5), just roll per year in the term as normal
other systems follow a similar pattern basically
that sort of thing. But I also will sometimes just give them a necessary skill if needed for the game. I remember years ago I was rolling up NPCs for a game, and one of the players (who used to be a game editor) said why don't I just create them as needed? And I don't because then the NPC has no backstory as generated by the dice, and as I've mentioned before, I worry that then I'll just keep creating the same NPC.
Yes, it is inefficient to do this manually, but I like rolling up Traveller characters. It may take several tries to get one that fits what I need, but in the meantime, I now have a bunch of other NPCs that may be useful.
