Hold the shrimp up so it looks like the letter C, with the tail making the bottom of the C. Push the skewer through the tail, stopping when the tip of the skewer hits the middle of the C.
Skewer 1 grape tomato and 1 basil leaf. Then, push the skewer through the top of the shrimp, so the grape and basil are enclosed inside the shrimp. Repeat with remaining shrimp, basil and tomatoes, placing each finished skewer inside a plastic storage container.
Place in the refrigerator until you're ready to go. Five minutes before serving drizzle skewers with dressing.