enter as it creams. allowing air, it makes whatever you're making light and fluffy. if the recipe called for oil not butter do the same thing but on a higher speed.
adding eggs into the mix is just as easy. crack the eggs into a separate small bowl. add one egg at a time. allow the mixture to beat one minute before adding another egg.
adding flour and the other dry ingredients. mix all dry ingredients in another bowl. add it into the wet ingredients slowly. if there is any milk in the recipe, add half of the milk and flour into the butter mix. then mix it and add the rest 