With the right preparation and practice beforehand, it can be done. If you really want to try your hand at making your own wedding cake just make sure that you have friends or family that can help you out with it. The first important thing is always to use a cold cake. Use the soft butter cream recipe. It is light and fluffy and not too sweet. But you can make it simply by adding confectioners sugar and vanilla to whipped up unsalted butter. After your cake layers are cooled, you will wrap them in plastic wrap and freeze for at least a few hours, overnight is even better. This can be done even a few weeks ahead if needed.
You can cut one cake to make two layers after they have cooled, but before they are put into the freezer. Two for every cake to slide under the cakes as you work with them and to serve as a base for every finished cake. The cold cakes will solidify the buttery mixture so that the layers will not slide around while frosting the cake.
After frosting you should end up with some icing further out than the edges of the cake. It should be thick, you will be scraping the excess off later. Get the butter cream thick on the entire cake and then scrape it down to perfection later. Some of the icing will form a ledge that is slightly higher than the top of the cake. Once the sides looking good, start working the top edges. This part takes a lot of practice so work it carefully with more practices.