Building a character from scratch can be quite a daunting task for some. What is their history? their beliefs? Where do they come from? What kind of skills do they have? Sometimes while writing a story you may come across a question you haven't answered already, and then you have to stop and make a decision. It can really mess up the flow of your writing if you constantly have to stop like this and figure out what your character can and cannot do. At the same time if all of your characters can do the same things then they all seem like the same character. Each one needs to be unique. They also cannot be perfect. Even Superman fails sometimes. I have developed 4 steps to help build characters.
1. Make a Character SheetThere are tons of resources for building a character sheet. The best character sheets you can use are already there for you to use for free. Many pencil and paper role playing games have done all of the hard work for you. You just have to fill in the blanks. There are also several programs that are free to download that can help you on your way. I do not use any of these programs, so I do not have any recommendations.
My preferred character sheet utilizes GURPS. GURPS stands for Generic Universal Role Playing System. You can learn more about it, and download a free copy of the blank character sheet at http://www.sjgames.com. You don't have to use their source books, but I find them highly useful. There are a lot of attributes in these books that can give you ideas to help you decide how you want to craft your character. Sometimes you will come across things that you hadn't thought about, but will be perfect for your character.
This can be a time consuming project, but it can also be very rewarding. You get to lay out all of each characters skills and attributes. This will help make your characters more realistic by giving them limitations. Holding your characters to these limitations will keep them from doing something out of character. That doesn't mean that your characters can't evolve. Update the sheet as needed. The GURPS system is very flexible, and there are guidelines for adding anything that may have been overlooked as needed.
2. Write a DescriptionThis would be a physical description of your character. Some character sheets will give you a space to write this, but I always find that they don't give you enough space. Most character sheets will leave you a small space to draw a picture also, but if you are anything like me then your character will end up looking like a stick figure at best. Frankenstein with balloon animal hands at worst.
The basics are obvious like height, weight, eye color, hair color, etc.. I also like to include a few other things. Personal fasion, how they carry themselves, hair length, and unique attributes. Personal fasion depends on several things like their position and station in life. They may wear a uniform most days, or they may wear a suit and tie. If they are young they may follow whatever recent trend there is. If they don't care about fasion they may dress for functionality or comfort. Unique attributes could include anything from a mole on the upper lip, to scars, or perhaps an unusual birthmark.
3. BackstoryThis is a personal history of your character. Again the obvious comes into play like where they were born, their parents, what they do for a living, etc.. I like to craft it like another short story. A synopsis of their life story up to this point. It doesn't have to be entertaining. Just a list of events and facts.
Their history is what makes them what they are today. Try to explain why they are who they are. When a sensitive subject comes up that could cause the character to become agitated or violent. The best predictor of future behavior is past behavior. This for me is the easiest part of creating a character. I start coming up with ideas before I do anything else. The only reason this is third on the list is the fact that the time it takes to complete the first two steps gives you time to think about the story of this character's life.
4. Find the Character's VoiceYou have all of the pieces. Now it's time to figure out how your character will sound to your readers. Everyone has a way of talking that includes phrases that most others do not use. If you don't craft a voice for your characters then they will all sound the same. They will sound like you.
Each piece of the character will influence how they sound, but where they come from will have the biggest effect on their voice. For instance, different areas of America will call beverages like Pepsi different things. Some areas will call it soda or pop or coke. I have heard the shopping carts in stores like wal-mart called buggies. You know where they come from by now. Decide what that means as far as how they speak. Would they have an accent? Do they use terms to describe everyday things that are different from what other characters might use?
Other parts of the character's past will also have a large influence. If they are deeply religious then they will make many religious references. If they are into sports they may make baseball analogies. Create certain phrases that the character likes to use that are unique to that character. Other characters may use the same phrase now and then, but not every character will.