In a small bowl, whisk together the vinegar and oil; season to taste with salt and pepper.
ASSEMBLE THE SALAD:
Add the greens to a bowl, and toss 1 tablespoon of the vinaigrette with the greens to just moisten the leaves. Divide the greens onto 6 plates. Top with watermelon and avocado. Drizzle the salads with the rest of the vinaigrette.
Sprinkle the salads with feta, nuts, basil and chives.
Notes
If you don't have raspberry vinegar on hand, try subbing rice vinegar, orange juice or pink grapefruit juice.
If counting WW Points, be sure to use reduced fat crumbled feta cheese.