How to make a perfect cake frosting?

Try this recipe: Cream a stick of softened butter (not margarine--use real butter) with an electric mixer until it is soft; gradually add 4 cups of powdered sugar to butter (be careful while adding you don't want the sugar flying all over you and the kitchen); mix until the sugar is well incorporated. If it gets too thick add a little milk to soften it up so you can keep mixing just be careful to add a little at a time so that it doesn't get runny. Now, add a quarter cup of cocoa powder to your mixture (or a little more if you like it more chocolate-y). Mix well. Add a teaspoon of vanilla extract. Mix well. If it is too thick, add a few drops of milk; too thin, add a few spoons of powdered sugar. Enjoy!!

it's very much depends on what kind of frosting you referring here.. I usually make very 'secure' frosting such as whipped cream, or choc ganache since my family loves chocolate. A double chocolate cake, (base and frosting) will always be a welcome at home any time. I find frosting with choc ganache is easiest as I can do both soft and stiff.. :D

Honestly I have no idea. I'm not good at making icing either. Whatever I attempt to make it's usually too runny so then I add more whatever and it's thicker but doesn't taste right. But you know even the store bought frostings are not always the easiest to apply sometimes I end up while Im spreading it puling up bits of cake w/ the frosting oh so very annoying!

I've not had any frosting nightmares as long as I follow the recipe exactly. You also need to make sure your cake is completely cooled. Frostings won't stay put without that. Occasionally, I'll come up on a powdered sugar glaze that the recipe calls for the cake to be still warm but I wait until it's cool as even glazes stay better on cool cake.

Mine never comes out right either. I usually end up buying the frosting. I envy the people that can make those delicious frostings and glazes!

you should consider the viscosity of your frosting if its thick or too thin, If your going to make a ganache then you should consider letting it set for a while(don't refrigerate) since the hot cream and melted chocolate will still be runny and might end up in the bottom. If your going to make royal icing it will set quickly and the viscosity of a royal icing is quite thick so no need to worry about it setting in the bottom.