The prestee brand cups can be reused a few times but you don't really need to if the package already comes with 500 cups. I've used them for mouthwash, carbonated water, soda, water and some snacks. Since the cups are small they can be stored away easily in small stacks. I keep a few in my bathroom cabinet, the kitchen cabinet and even in my car. These are good to use when someone wants a taste of your drink and you don't want them using your cup or drinking utensil. They are thin 3oz paper cups but they are still sturdy enough to hold your drink or mouthwash long enough to drink it/ use it. So far I've had no leaking which is great but I also haven't let the liquid stay in the cup fot too long. I've also used some cups to control my servings of small loose candies such as chocolates. These are also great for crafting, especially when you need a small container to hold beads, paint, water, etc.