STEP 1: Plop the frosting onto the cake
Scoop a mound of frosting on top of the cake (after the crumb coat).
STEP 2: Spread the frosting
Use a spatula to spread the frosting around. Do not let the spatula touch the base of the cake. Continue by turning your cake on a turntable and gliding the spatula along the frosting.
STEP 3: Spread the frosting down the sides
Spread a thick layer of frosting onto the sides of the cake, turning all the while and pulling excess frosting from the top edges down onto the sides.
STEP 4: Clean your spatula
Keep a cup of hot water close by and gently dip your spatula to quickly clean it.
STEP 5: Clean up the top edge
Knock down any frosting that is poking up and spread things out a bit as needed to make the edge fairly even all around.