Homemade frosting--Attempt #1

Shortly after I finished my cake decorating class, I just wanted to practice, practice, practice. I was finding every excuse that I could to decorate the cake.  I tried to make a few frostings on my own, which was awesome, however, it took a lot out of me to make my own frosting, bake a boxed cake, color the frosting, and then finally decorate the cake, all in one nights time. (remember that I said before that I was/am a procrastinator).  The only good thing about this, was that I was making a cake for a friend, that used the same colors that I could use to make a St. Patty's Day cake, just 3 days later... Anyway, I decided that from now on, or until I get a little bit better at the decorating part, I was going to buy frosting from Michaels, using my 40% off coupons, and then used boxed cake mixes. So, here are the cakes that I made with my 1st attempt at homemade buttercream frosting, and boxed cake mixes.  The frosting tasted good, but got soft very quickly, making it hard to make 'good' decorations.