First, take apart the greens and wash and thoroughly dry them. (Soggy greens dilute your salad dressing now and spoil quickly if you’re storing them for later use.) Line a plastic or glass container or a resealable plastic bag with paper toweling. Place a single layer of greens on the paper towels, adding more layers of toweling as you add more greens. Place the lid on the container or squeeze the air from the plastic bag before sealing and refrigerate.