It may seem silly, but the Sims actually helps me when it comes to character creation. Since I'm a geek of sorts, I have a bunch of custom content and I can make them look exactly as I picture them. If I have a plot that's roaming in my mind, I'll just open up the Sims 2 and just... make them, y'know? The personalities typically develop when I'm making their faces~. Then, if I really, REALLY want to stick to an idea, I'll create the house they live in and furnish it. It paints a really clear picture for me when I'm writing, and it helps me describe it better.
For example, this is Noah. : D
I just made him two days ago after I got a really good idea for a story.
He's a pretty-boy, and I made him look somewhat exotic, but I can't think of what ethnicities I want him to be. :s
Afterwards, when I think I have their looks ready, I'll open up notepad and write out their age, name, job, ethnicity, hometown, personality, background, wants/fears, and their role in the story. Looks are probably easiest for me. The hardest part, I think, is ethnicity and background. With Noah, I wanted him to be mostly Swedish, Polish, and only 1/4th Vietnmaese. Then I thought, "well, he doesn't really look Asian..."
And the problem with background information is wanting it to be somewhat interesting, but not cliche and overwhelming, such as a tragic past... :s
AHH. THIS IS SO LONG.
I'm sorry. <3