I learned from a friend that a salad is like a stew with uncooked foods--whatever you have goes in it. So my salads are generally different. But one of my favorite combinations is:
Mixed greens (one kind of lettuce is so-o-o-o boring)
Berries (strawberries in the summer, then raspberries, and now blueberries)
Nuts (almonds or walnuts work best) or seeds (sesame is my favorite but sunflower works)
Feta or soft goat cheese if you have it, but not necessary
A fruity viniagrette dressy--my favorite is bottled Raspberry Walnut viniagrette, but you can make your own with balsamic vinegar and olive oil.