This might be familiar if you are from my country(indonesia). We use to decorate the cake with the styrofoam background for the birthday cake. Then, we add up with some other things from butter cream. The ready made decoration styrofoam are very easy to be find in indonesia. They are made in many different styles that suite the themes. It is easy and good to use when we are short of time.
For this cake, I added up a little girl made up from fondant wearing a "hula"skirt as the party theme is Hawaian dance. Flowers everywhere. Louisa, the birthday girl, loves every cuty cuty things. So, I put some "hello kitties" dolls to make the cake looks merrier.