I've been creating a set of characters for months now, and I'm to the point where I've begun writing. I'm four paragraphs in, and one of my characters asked the other one, "What do you like to do?"... and I'm like, oh crap! I didn't think about this. I was too focused on her special abilities, what makes her unique, rememberable, etc.
So, as I now brainstorm just what this girl does in her off-time, I came up with a great idea. For skills and hobbies, I pulled out my GURPS book (Because why not? There's a million skills!), and I've actually found this to be a great resource for character building in general outside of role playing. But what else do you consider when you create a character?
I typically do the bare minimum like what my character's likes and dislikes are, their birthday and zodiac sign. I thought about possibly incorporating blood type as well but I haven't done this for any of my characters at the moment. Would be pretty cool to incorporate their personality to be based around their zodiac sign and such. For example I'm a Taurus and I'm very stubborn. It would be fun to write a stubborn character lol.
I do this a bit too... I always start my characters with the four big questions.
What does the character want or desire (pick 2: one that is really their heart's desire, and one that's a side idea that also makes them happy)?
What does the character try to avoid (pick 2: one that is an absolute fear or hatred, and one that's just annoying to them)?
What strengths might help them achieve their wants and desires (pick 2: one might be supernatural or magical, but another might simply be a cool skill they've picked up)?
What weaknesses might be preventing them from achieving their goals (gaining their want also brings them closer to the thing they are trying to avoid, their strengths link to the thing their trying to avoid, achieving a want requires embracing an enemy in their life, etc.)?
Building up inherent tensions and contradictions in a character makes them more interesting.
Beyond that, I've applied the Myers-Briggs archetypes to characters (to varying degrees of success), as well as giving them eastern and western zodiac signs ("oh, she's a Taurus Snake") to add stereotypical ideas that might drive the characters motivations and choices when their big desires and fears aren't currently in the picture. Similarly, we might use combined pros and cons for a character when we don't know what their choices might be...("Choice A would weaken the things she's trying to avoid, Choice B would get her closer to her goal, being a Taurus favours the first action so that's how she'll go this time.").
Yeah, it reduces characters to some fairly predictable outcomes if all the variables are known, but part of the fun comes from other characters not knowing the elements that are driving their choices.