Watermelon holds a lot of water, so drain off the excess liquid after cubing to keep the salad crisp rather than soupy. Swap the feta for goat cheese or crumbled paneer, or use basil instead of mint for a different twist. A pinch of Aleppo pepper adds subtle, fruity heat. This salad is best served fresh; if making ahead, keep the feta and any garnishes separate and toss just before serving. A short 15-to-20-minute chill deepens the flavors beautifully.