Here is an article from Marta
Many garments look their best when hung on proper hangers in closets that aren't overcrowded. Other clothes benefit from being neatly folded. Shirts and blouses made of linen, rayon, or 100 percent cotton will stay virtually wrinkle-free when hung upon hangers. Use padded hangers for slippery silks and satins, as well as delicate fabrics that crush easily, such as velvet, raw silk, chiffon, and taffeta. Curved suit hangers help maintain the shape of outdoor jackets, overcoats, suit jackets, and blazers. Skirt hangers have moveable clips to accommodate most skirt sizes and styles. And trousers hang nicely over the sturdy rods of wooden hangers, or held by the cuff with clamping trouser hangers.
Knitwear, including tops, pants, skirts, and dresses, should usually be folded. However, if you're tight on drawer space, a sweater can be folded in half, shoulder to shoulder, and draped over the bar of a wooden hanger with a piece of tissue paper in between. Casual pants and shorts made from rugged materials, such as jeans, khakis, and corduroys, also can be folded. And you should fold long evening dresses, particularly those weighted with ornamentation, because hanging can distort their shape. -Article courtesy of marthastewart.com
And here is a little tip I learned while working at The Gap in high school...use a cutting board to give your clothes a perfect fold!
Bed, Bath & Beyond