The petal effect technique is easy to achieve. I didn’t have any frosting, so I used a peanut butter filling to demonstrate the technique. I hope this helps.
In the first picture, I made 4 big round dots with a Wilton tip 12. I then pressed down slightly on the dot (near the edge) and dragged the spatula outwards, wiping off the spatula after each smeared dot (see photo six). Next, I added 4 more dots on the ends of the previous smeared dots. In the fourth photo, I again pressed down slightly on the dot (near the edge) and dragged the spatula outwards, wiping off the spatula after each smeared dot. The fifth photo, shows a third layer. You will continue to do this until you have completely decorated your cake. End the design with 4 big round dots to look like buttons.
Of course, this looks a lot better when using buttercream icing. Check out the Pink Ombre Petal Effect Cake post to see the front of the cake. I also discuss how I achieved the pink colors.