Heal chapped lips. Remove flaky skin with a damp washcloth, and coat your mouth with a waxy balm. Let it soak in, then remove any excess. (Otherwise, color will slide off easily.)
Prevent feathering. Line and fill in lips with a nude pencil before applying color. This will help the shade last longer and define the shape of your pout, too.
Layer color in two thin coats, blotting after each. If you have thin lips, opt for light to medium violets; darker tones have a minimizing effect.