Take a clean towel. Buy a number of kinds of lettuce, for instance rucola, lettuce and oak leaf lettuce. Cut it into your preferred size for on your plate, wash it well and let is dry on the towel. Then roll up the towel when all the lettuce has dried and tie the end with rubber bands. Keep the roll in the crisper compartment of your fridge and take from it what you need, when you need it.