The subtle flavors of delicate mixed greens should not be masked by heavy dressings, like cream and highly-spiced ones.  A splash of olive oil or balsamic vinegar can often be all that is needed. French vinaigrette, a light dressing made with cider vinegar or lemon juice, oil, salt, and a pinch of dried mustard, is the perfect mate for delicate greens.  If you are calorie-conscious, make your vinaigrette with the following formula: 1 part lemon juice or vinegar, 1 part oil, 2 parts water, salt, and dried mustard. You can add garlic and/or light herbs like dill or thyme.