I have successfully covered single layer cakes just fine, but then I go to do a double layer cake and the height of the cake completely threw me! There was so much excess fondant hanging down around the sides couldn't smooth it correctly. I messed up two different cakes, both 2 layered ones. I smoothed from the top down in a corkscrew method. Any suggestions? THANKS!
Perhaps if you watch the video at atecousa.com it will help.
I put the cake plate on top of a pan that has a smaller diamater, so it's lifted off of the counter and the fondant can hang down. Then I smooth and trim. If it's a stacked cake, the fondant goes down to cover the edge of the cake board. If not, I trim as close as possible, then tuck any excess (I'm talking little bits here) under the cake.
It helps me to roll out my fondant for round cakes on the wilton cake dividing wheel (I've only owned the thing for 8 years and it took 7 and a half to find a good use for it ). Anyhow, the diameter of the cake pan, plus 2 times the height of the cake (measured with a ruler after the middle is filled) plus an inch has never let me down yet. The circles on the dividing wheel are perfect for getting the right size.