Washing should be avoided if possible, as once the leaves are wet it’s difficult to dry them again and you simply can’t get dressing on to wet salad leaves.
Take a damp piece of kitchen paper and wipe each leaf, the lettuce leaves remain dry and can more easily be coated with dressing.
If you have to wash the leaves:
Plunge the separated leaves briefly into cold water and place them in a salad basket,
Either hang them up after a good shaking or else swing the basket round and round outdoors.
Finish off by drying the leaves carefully with kitchen paper.
Never use a knife when you prepare lettuce, because cutting tends to brown the edges of the leaves, use your hands to tear them.
Breaking up the leaves too soon can cause them to go limp quickly, always leave them whole, if possible, until you’re ready to serve the salad.