
Add the watermelon cubes, cucumbers, and red onion to a large salad bowl and gently toss the ingredients together.
In a separate small bowl, add the red wine vinegar, lemon juice, olive oil, and ⅛ teaspoon of salt and whisk the ingredients together. Drizzle the dressing over the watermelon, cucumbers, and red onion. Toss again.
Add the basil, mint, and feta crumbles to the salad and season with the remaining salt and freshly ground pepper. Set aside.
Heat a small skillet over medium heat and add the pine nuts to the skillet. Toast the pine nuts for 3-4 minutes until golden brown, being sure to toss them while they toast.
Sprinkle the pine nuts over the salad and serve immediately.