Start with the stem (character's gender and age), and branch out. Where does she (I'm using "she" for simplicity) live? A farmhouse at the end of a dirt road? A villa in Italy? A high-rise off Fifth Avenue?
What about values and beliefs? Did she go to a rural Baptist church or was she raised by Buddhists? Is she a backsliding Catholic or agnostic? What's her personal motto? What image does she strive to project to others? Why? Is she successful or does her true personality break through in words and actions?
What is she hiding from you? Make her tell you.
Does she have a mannerism? A favorite saying?
What scares her--really, really scares her? What's her strength? Weakness? What happened to her at age 3 that shaped her world-view? Find 6 milestones and describe a critical event for each one, something that formed your character's world view.
Do you know her name? If not, don't worry. Pick one. The true name to fall out of the sky. Just like a leaf.
Pay attention to every detail on your leaf. No vein is too small. You can't learn enough about this person. Listen. How she she talk? Is her voice rough and gravelly or soft and lispy? Strident, nasal, girlish? What's her accent? Does the gap between her front teeth make her self-conscious?
No, you won't put every detail into your book. But somehow they shine between your words. The more you know, the more it shows, and your character will leave a distinct scent on the page. You'll be writing from a powerful place, a place that can't be explained, and the only way to get there is to do the hard thing and study every line and furrow on your leaf.
It's impossible to know too much about a character.
Question: But isn't this difficult and time-consuming?
Answer: How much do you want to write? This want should be overpowering and unstoppable. If you have a choice between writing and having lunch with a pal, you may love your pal dearly, but you'll pick the writing.
Question: Speaking of air, do I have to pull my character's details out of the air?
Answer: Yes and no. But you can learn simple techniques to jump-start characterization.
Assignment 1: Buy a notebook. Write your character's name on the first page. If she doesn't have a name, give her a temporary one. Write down details. You can change them later, but for now, start branching and exploring.
Assignment 2: Find a tray and "shop" your house, looking for totems and objects that relate to your character.
Assignment #3: Create a mosaic. Add photos that bring your character to life.
(I made this one for a dear writer friend. I used http://www.bighugelabs.com/)
One of my mosaics (made in Picnik).
Next Post: A simple way to jump-start a character and fill in these details.
Coming in July: Solitude and Everything Else: Writers Talk About Writing