When I first began leveling my cake layers I was amazed at the change it brought to the finished look of my cakes. It also makes them more sturdy.
I have read in many books to use a knife to level a cake. I tried it...and tried it...and finally decided that I can't cut a straight line to save my life. Then I went out and bought a cake leveler. It was very inexpensive and saved me so much agony.
cake board you made earlier and spread a dollop of frosting on it. Place the first layer on your cake board, cut side down. Then spread a layer of frosting on it.