Just remember a drink that I used to make accidentally, which actually tasted quite good. Normally, I cut up watermelon and blend with a couple of ice cube in the blender.
That day I was cooking a vietnam style dinner and while sweating away in the kitchen, I thought it would really cool me down with a refreshing drink, hence, I did my usual watermelon blend. I went back to cutting my mint vegetables for the soup dish I was making. Accidentally, I had drop a 2 stem of mint leaves into the drink. It turn out quite nice and added a kick to the watermelon juice.
2 slices of watermelon
5 mint leaves
3 ice cube
Combine all and blend.
To upgrade it into a mocktail, check out another version at