I like simple salads, but sometimes if I have some odds and ends in the fridge, I will toss them in to use them up. I have some other suggestions to add more to this salad, but not to complicate your life. Other additions that are nice here are capers or olives, shaved Parmesan instead of the feta, roasted red peppers, or paper thin raw zucchini slices. You can also swap sliced stone fruit like nectarines for the tomatoes.