I know, I know. Everyone and their aunt has character sheets they use. But I'm one of those who never used to use them. I made things up as I went along and thought that was the best way to go. Then I discovered I was doing something that I find to be very annoying when some of my favorite writers do it - I was screwing up my own timeline and my characters.
I would have characters talk about things that they did that I never planned for them to do, and when I'd go back and read I'd find that I came up with a reason early on in the book why they couldn't have done it. I'd forget what they looked like. I'd give them character traits that went against what I'd initially had in mind for them. In short, I was messing up my own characters and with nothing to help me keep them straight it was a royal pain.
So I've devised my own version of a character sheet and I thought I'd share that with you. It's just some basic information about the characters. You can, of course, make them as detailed as you want. But I found this is what works best for me.
The first section is vital statistics. How tall are they? How much do they weigh? What color are their hair and eyes? What's their skin tone? These are basic things you need to know how your character looks. If they have tattoos or scars, this would be the best place to put those notes.
The second section is family. Where did they come from? Do they have any siblings? What about aunts and uncles? Grandparents? You don't have to go that far back in their timeline, especially if you don't expect to bring any of those family members in or the family members don't play an important part in the character's life. Even if their only purpose is to die to give your character drive to move forward with the adventure, put them on the character sketch. You don't have to give them names. I do, but I'm weird like that.
The third section is special characteristics. What makes your character so special? Are they hyper intelligent? Faster than everyone? Stronger than the strongest people in their village? Can they fly? Even if discovering this special characteristic is part of the story arc, make sure you write it down so you remember to put in the appropriate cues leading up to it. Another good thing to put here is their flaws. What makes them less than perfect? What are they afraid of? What is their attitude towards people?
The fourth section is the biography. This is where you get more detailed about where they came from. What is their history? What made them who they are now? Who were they before they became part of the story?
The fifth section is optional, and even I don't use it all the time. If you want, you can add some notes to the character sketch about how your character is going to evolve and change along the story arc. If you're like me and still don't know exactly how they're going to change, then obviously you wouldn't want to put in this section.
If any of this is useful to you, please feel free to adapt it to your own needs. I've adapted my method from reviewing several different character sketch outlines.