I have very few recipes with the words, "Don't change a thing!!!". For others, I usually start with a good recipe. I can read a recipe and tell what it will be like. I used to make it exact the first time, but I don't anymore. I love reading recipe books so trying the few special ones is what I enjoy. But just like savory cooking, I have to make it mine. Some recipes like the one I am sharing the changes on another thread just change the method. But even that recipe was adapted from King Arthur Flour's white cake. Others look very little like the original.
Because I learn from top chefs, most of the time the changes are just personal preference.Then once you have an arsenal of great recipes, adjusting flavors to create new flavors is easy. For example, a yellow cake to a lemon cake.