Suede shoes are vulnerable to scuffs, scratches, and stains, and they're hard to clean.
Brush out dirt. Make sure your shoes are dry, and use a suede cleaning brush to gently brush away dust or dirt. Brush in the same direction (don't go back and forth) to lift dirt out and make your shoes appear newer.
Remove scuff marks. Use the suede brush to vigorously brush scuffed areas back and forth.
Remove water stains. Water can discolor affected suede. To solve this problem, wet the entire outside of the shoe by applying a light coat of water with a nail brush. Use a sponge or dry cloth to soak up excess water, and then let the shoes dry at least overnight. Be sure to insert a shoe tree into the shoe while it dries so that the shoe doesn't shrink or lose its form. Once the shoes are dry, go over them lightly with a suede brush as in step 1.
Remove oil or "unknown" stains. Use the suede brush to scrub the stain as you would for a scuff. Use the nail brush to scrub stubborn stains with warm water. Grease stains can be particularly difficult to remove from suede, so badly stained shoes may never look good again.
Protect your suede. Spray a coat of suede protector spray on your shoes when you first get them and after each cleaning. Follow the manufacturer's directions, and make sure to remove excess dirt before spraying the shoes.