Empty your closet. Pull out evcerything inside so you can see it all. (Schedule two to three hours for a small closet, or three to four hours for a larger walk-in.) Find a new and better home for anything that's not apparel (decorations, books, photo albums, etc.). Once the closet is empty, give it a thorough cleaning.
Sort your clothes. Categorize clothing into three piles: warm weather, cold weather and transitional items, like camisoles and T-shirts that can take you through in-between weather. Scrutinize your wardrobe for items that no longer fit or that you don't wear anymore; consider selling them at a yard sale or donating them to charity.
Evaluate your system. Decide if your current storage plan is working. Do you have enough space for dresses and winter sweaters? Is it easy to find shoes and accessories? Draw a map of your closet to figure out the best place for everything. Bring your drawing to a home improvement store to find the best solutions for your storage needs.
Put everything away. Check over your clothes to make sure nothing needs cleaning or mending. Pack seasonal stuff in storage containers and place them in a place that is dark, cool and dry. Hang your current and transitional items by type and then by color, so you'll be able to create outfits more quickly. Save hanging space by stacking folded sweaters, sweatshirts and T-shirts on shelves in your closet or in a chest of drawers.