Have a short (I mean it -- SHORT), great quote written on the board when students come into class. They will read it and begin to focus on the topic of your lesson before you even say a word. I've done this with gospel quotes and other saying, like "With Great Power comes Great Responsibility" from Spiderman. It helps students get their minds on topic even before the prayer. If they already know your lesson material, they will try to guess how you will use the topic in your lesson, which helps you get great comments and discussion.
EXAMPLE: On the board I wrote, "What are you worth to Heavenly Father?" (1 Corinthians 7:23)
EXAMPLE: During a class on temptation, I wrote this quote from the Art of War by Sun Tzu :
If you know the enemy and know yourself, you need not fear the result of a hundred battles.
If you know yourself but not the enemy, for every victory gained you will also suffer a defeat.
If you know neither the enemy nor yourself, you will succumb in every battle.