While tomatoes and corn are still going strong in the market, I love combining them in various ways with different produce and vinaigrettes. It is really hard to go wrong when you start with seasonal produce. Experiment using different raw vegetables; slicing them thinly makes almost any vegetable, firm or not, easy to eat in salads (like matchstick cut of raw beets).
Experiment with the vinaigrette, too, using different vinegars or citrus juice, if you want. The acid-to-oil ratio for a sharp, flavorful vinaigrette is about 1-to-3 for vinegars and 1-to-2 for citrus juice.