Use a 4-inch star-shaped cookie cutter (or any shape) and cut 16 stars out of the watermelon (about 1 oz each). Save the excess watermelon for another use.
Arrange the watermelon on a platter, then layer with cheese, arugula, 1/4 tsp olive oil and a pinch of salt on each.
Top with a final star, drizzle each with balsamic glaze and serve.