1. Use your hand to carefully smooth the top of the cake and remove any air bubbles from under the fondant. Be sure that you don’t have any jewelry on that might leave marks, and avoid using your fingernails, as fondant is easily marred and scratches are very hard to repair.
2. Now position your other hand on the side of the cake toward the top and press the fondant into the side. Use your hands together to press toward each other, forming the corner of the cake. It’s important to do this step quickly, as the weight of the fondant hanging from the top tends to form small cracks in the corners if the sides aren’t pressed in quickly. If you do develop small cracks, you can rub a little vegetable shortening into those spots which will help disguise them--especially if your fondant is white.