1. Remove any brown-edged, bruised, wilted, or old leaves.
2. Wash greens under cold running water, then separate the leaves and rinse them in a colander under cold water. If the leaves are very sandy or gritty, repeat the rinsing step.
3. Use a salad spinner to dry washed lettuce greens or shake them dry.
4. Layer the leaves between paper towels and store in a sealable container or plastic bag in the refrigerator. Cleaned lettuce will keep this way for a week.