Wash watermelon and cucumber under cool water. Cut watermelon into cubes and cucumber into thick rounds or half-moons. Crumble feta cheese and set aside.

In a mixing bowl, combine chopped watermelon, cucumber slices, and crumbled feta cheese. Gently fold together.

Drizzle olive oil or balsamic vinegar if desired. Toss gently. Add fresh herbs for additional flavor.

Transfer to a serving bowl and serve immediately for optimal freshness.

Store leftovers in an airtight container and consume within 1 day for best taste.