So this was one of my first beginner cakes. It's a two layer birthday cake. Its a simple fill in. I actually really like this technique with stars a lot. Its about the easiest cake you can do. Using a cookie cutter you stamp the outline of the stars (or in shape in fact!)!  Outline in one color using a plain tip (like a #3). Then use a star tip (like a #16) to fill in the centers. This technique looks great on all sorts of cakes. I like to use the mini-star fondant cutters on cupcakes to do this same sort of design. The best thing about this is how quick it is. You can do it all in one color using one bag with a coupler and have something that looks custom. Even better it's totally customizable. You can use hearts, flowers, any cutter you can think of... the possibilities are endless! This is definitely one I will keep in my arsenal for quick cakes!