Thread cherry tomatoes, mozzarella cubes, and basil leaves onto skewers, repeating until the skewer is filled. Repeat until you get the amount of skewers you want.
Place balsamic vinegar in a small saucepan. Bring to a simmer on medium-heat and then turn down heat to a low simmer. It will take about 10 minutes to thicken and reduce. Keep a close eye on it so it doesn't burn. When it coats a spoon, it's finished.
Take off heat and let cool for a few minutes. Drizzle over the skewers and serve. Enjoy!