To prevent food from sticking to aluminum foil when baking, you can use a few methods. First, lightly grease the foil with cooking spray or oil before placing food on it. Second, consider using a non-stick spray or a light brushing of butter or oil directly on the food itself. Another option is to use parchment paper as a barrier between the food and the foil. Additionally, ensure the food is not overcooked, as this can cause it to stick. Lastly, avoid using shiny, new aluminum foil for acidic or sugary foods as it may react with the foil.