Hey everyone I have found a very easy way to get both flawless achievements. Ok so start up a trick event with one or two people which ever achievement your going for, im not sure if they stack but they only take about 1 min to do each one. Ok so make sure your xbox controller is near by, and start the event. Now make sure you or both of you get a Flawless on the very first trick, then quicky press the xbox guide button. The game should have paused, now select back to main menu and pop theres your achievements!