I tend to have a mix, sometimes it is the class that gives me the initial hook, sometimes a cool idea I want to try, sometimes the story of the character.

After I've got the hook I tend to refine and adjust, get a cool trinket that makes me think of adding X, if I grab a morningstar instead of a sword that might mean Y. Just tweaking things until it is time for the game to start.


As to writing backstories, I tend to write a page or two. I try and keep it short, but it is way more interesting and useful to me than trying to write some motivation sentences. Especially since a lot of the ideals, bonds and flaws in the PHB are kind of crappy and/or useless.

I think the biggest use out of writing the backstory is the connections. Sure I can write "Make my Family Proud" under ideals, but that doesn't tell me who my family is, and if I begin writing and figure that my family is a noble house with a long line of clerics devoted to this temple, then I can do two things. 1) I can talk about them like real people and 2) I can find other motivations, things I might have missed or overlooked if I thought about them in distinctive chunks instead of as a whole.