When I started making cakes in high school, I kind of just went in blind. I didn't read any books or blogs, or watch any baking shows...I just went for it. And as a result, I made cakes that looked like this.
That is supposed to be a cake of my friend's face - and in case you were wondering...she does not look anything like this. But we all have to start somewhere, right? Obviously, I started in a place where there was a lot of room for improvement. After a few more cakes like this, I decided to it was time to open a book.
One of the first, and probably most important things I learned in my early research was the importance of a crumb coat. By definition, a crumb coat is a thin layer of icing that traps in all the cake crumbs. But, it also helps you to fill in places where your cake might not be totally even. The crumb coat gives you a solid base to start decorating on. It is kind of like the concept of using paint primer before you start to paint your house. This little coat of icing makes your life so much easier and if you skip this step, you run the risk of having little pieces of crumb in your final product. Kind of like this...
This is annoying, and as you can see, not very appealing. So do yourself a favor - and crumb coat your cakes. Crumb coating is easy. Once you have filled and stacked your layers, take a small amount of icing and spread it all over the cake. It is easiest to start at the top, and then work your way down the sides. Try to make it as thin and as smooth as possible. Once you are done, place the cake in the fridge for 15-30 minutes, or until the icing has hardened.
And that's it! You are done! And then, after the icing has set up in the fridge, you are free to start decorating. Once you have done this one time, you will see the difference it makes in your final product. Take it from me...it will only make your cakes better! And as a bonus tip...I suggest never trying to make a cake of your friend's face. No matter how good a cake decorator you are...something about it just always seems off.