Mulligan for your draw cards (1 Mana), focus on minions, anything bigger than 2 mana - except maybe 1 Razorfen Hunter - goes back into the deck. If you start with two Power Word: Shield, one goes back into the deck. Keep one Shadow Word: Pain against mages.
try to find a good curve play until turn 4, anything bigger than 4 Mana gets returned, except a Holy Nova against Paladins or Hunters, again focus on minions.
Just check the video, can't say much more than what is already written above.