Project Runway's Tim Gunn advises starting by taking everything out of your closet and making four piles: trash, donate, repair and soul-stirring. Take care of the first two piles and take the clothing needing repair to a tailor. (Another idea is to make a fifth pile to take to a clothing swap. You can look for one in your area or host your own.)
Now that you know what you have, make a list of what you need. Do you have eight pairs of boyfriend jeans but not a single dressy pair in a dark wash? Do you have shoes in every color of the rainbow and lack a professional pair of pumps in basic black?
What is the dress code at work? What do you typically do on the weekends? A single 23-year-old will have different social events than a married 35-year-old mother of two.
Clip pictures from magazines to help you identify your personal style. It's easy to get sidetracked and forget that bulky turtlenecks look awful on your busty, petite frame or that skinny jeans do your thighs no favors. Look at the pile of clothing you kept, focusing on the clothes you wear on constant rotation. What similarities do you see in the styles and colors?
Buy clothes that look good and fit well right now. Too often we buy things that are slightly off for one reason or another. Good enough is not good enough. You should love what you see in the dressing room mirror, or it will be destined to hang out on the hanger with all of the non-soul-stirring clothing.
It's better to have a streamlined closet with pieces you love than to have one bursting at the sliding doors with nothing to wear.
For more tips on cleaning out your closet and building a functional wardrobe, including style advice from designers and savvy fashion bloggers, check out How to Stop Buying Clothes You Never Wear at GetRichSlowly.org.