T.H.
Kroger has a very colorful edible starwars picture that you can actually have put on the cake. I made my sons cake two tiered. I put the picture to one side of a sheet cake and on the blank sheet cake side I stacked a small cake on top of it. I placed his star wars figures on top. You could use the figures in a mock lightsaber battle on top of the smaller cake. (or small ships if you have them) My child is allergic to colors in frostings, so my smaller figures smaller tier on the cake had no colors in the frosting, but you could use colored frosting to make it look like they are fighting on top of rocks. (or brown sugar)
Starwars themed cake is so much fun to do. Good luck with yours.