What am I doing wrong, every cake I bake fails?

First, don't put tin foil over your cake. That's a process used for meats. Make certain you are using the proper ingredients. Don't use spread for butter. If you are using glass or dark pans lower the oven temperature by 25 degrees and also make certain you're the proper size pans and use measuring cups and spoons. Don't try to guesstimate with coffee cups and tableware. Good luck.