A good method to remove burnt on food is to bring to the boil some water mixed with lemon juice and vinegar in the cookware. This will help break down the food particles making them easier to remove. 
           
Every time you use the cookware, make sure you clean it thoroughly using warm soapy water and a soft cloth. Avoid using scourers, Brillo pads or steel wool as this will scratch the aluminum. Do not put your cookwares in the dishwasher as this can damage them leading them to oxidize quicker. 
                       
Once a month, or if your cookwares are used frequently, soak them in some oven cleaner. Once you have soaked the cookwares, wash them well in soapy water and rinse them to make sure there is no residue left on them. Most of all, do not use strong chemicals when cleaning your aluminum cookwares. Some products such as bleach are will damage the aluminum if they are used and are also dangerous to you if any residue is left.