Made simply with red wine vinegar, olive oil, salt, and pepper, the dressing works because it allows the fresh tomato and cucumber to shine while enhancing their flavors.
You can adjust the ratios of your ingredients to fit your tastes or add additional ingredients like fresh or dried herbs, Dijon mustard, or even a bit of honey.
For a sweeter, richer flavor, you can use balsamic vinegar in place of red wine vinegar, or make a richer salad by adding sliced onions, peppers, feta cheese, or fresh herbs.