Have your cake, crumb coated with frosting of your choice in the fridge and ready. Also have your jello fondant ready for use.
Prepare your plastic mat with a thin layer of shortening to prevent the fondant from sticking.Prepare your fondants.
Break off a chunk of the jello fondant (a little larger than a golf ball) and warm it up in your hands. Roll smooth using the guides on the roller to get it even. Use the piping tip to cut out circles.
Set half aside and add a thin layer of luster dust over them with a dry paint brush.
Continue to make circle cut-outs with all the other fondant colors you intend to use. I used about 75% more jello fondant than premade fondant.
Now start arranging them at the bottom of the cake and randomly add circles to the base. They should stick to the buttercream frosting without need for any other adherent.
Offset the second row and continue around the cake. I had 5 rows going around my cake, the last one, bending over from the top down the side.
For the top, start at the outer perimeter and go around in an overlapping fashion. Continue to build toward the center, then overlap the final circles in the center as best as possible.
Cover and refrigerate until ready to sing Happy Birthday.