Blend. Chill. Drink. Repeat!
In a blender, puree about 6 cups peeled, chopped watermelon (from about half a 5-pound watermelon); 1 lb. ripe juicy tomatoes, halved and cored; 1 lb. strawberries, hulled; 1/4 cup chopped fresh mint; 2 tbsp. fresh lime juice; and a pinch of salt until very smooth, 2 to 3 minutes. Strain into a pitcher, pressing on solids with a spatula to release liquid. Stir in 4 cups cold water. Refrigerate until cold, about 2 hours. Serve over ice, garnished with tomato rounds, mint sprigs, watermelon wedges and/or lime wheels.