I want to see little details that make the NPCs more real. BioWare seemed to pick a defining characteristic, and write the
NPC around that, and forget anything that made them more 3D.
Jaheira: abrasive, maternal, and assertive, but maybe she also plays a musical instrument, likes strawberries, and can't wink.
Minsc: direct, childlike, uncomplicated, but maybe he is skilled in the Rashemi art of dancing. It isn't unusual for cultures that revere warriors to develop ritual dances for them.
Jan Janssen: annoying, long-winded, and... well, Jan-ish, but maybe he's also a good cook, if you hide the turnips.
Anomen: sure, he's got issues that define his personality, but he must have done *something* with his time besides cultivate angst and an inferiority complex. Maybe he also enjoys reading about heraldry, is on an eternal quest for exactly the right pair of gauntlets, and likes chess.
I'm sure you get the idea.