To prevent food from sticking to aluminum foil, lightly coat the foil with a thin layer of cooking oil or non-stick cooking spray before placing the food on it. This creates a barrier between the food and the foil. Alternatively, you can use parchment paper or wax paper between the food and the foil. If you're baking, you can also line the foil with a silicone baking mat. Remember to avoid using sharp or pointy objects directly on the foil as they can tear it, which could lead to food sticking.