Yes indeed: the triple backflip is still in the beginner category, because it doesn’t take much to do this trick.
Simply gain more altitude with your quadrocopter and hold the direction even longer. Make sure you are using a roll/yaw/pitch rate of at least 0.3 in MultiWii Conf.
watch on youtube: http://www.youtube.com/watch?v=SKYdVZTXmDM
When you are already familiar with the casual backflip, the double backflip is very easy. Simply gain more altitude and hold the direction a little longer.
watch on youtube: http://www.youtube.com/watch?v=gJuP1NnrdOo
Altitude is your friend, first time doing a backflip with your quadrocopter! Find more basic tricks here.
watch on youtube: http://www.youtube.com/watch?v=1fh_D6R1O9Q
Okay, grass roots: the roll is the easiest flip-like trick with a quadrocopter. You can do a roll to the left or to the ride side.
Full throttle to gain altitude, then full aileron to the left and throttle down to about 50%. Keep aileron to the left until the quadcopter is in level position again.
At half turn backup throttle again to keep the altitude. Usually you need full throttle for a short time to intercept the flip movement. Altitude is your friend! Find more basic tricks here.
watch on youtube: http://www.youtube.com/watch?v=S4sAJM1uRD0