Some things to try that are pretty easy when you are really high (3 mistakes)

Elevator---- Slow the plane down and feed in full up (high rate) elevator. Maybe add in a little throttle but not so much as to accelerate forward or climb. If you do it right the plane will be falling but not moving forward and the wings will be level. JUST enough throttle to keep the plane stable all the while holding full up elevator. The wings may rock a little and it may want to turn this way or that so you have to steer with the rudder and minimize wing rock with the ailerons. If you get it right the plane will slowly start to descend almost vertically wings level! Manage the throttle to assist in just holding the nose level and let the plane descend as low as you dare. To fly out throttle up and ease out of the elevator and fly away.

Waterfall--- Just put it on high rates and from a low speed give it full down and full throttle, learn to manipulate the ailerons to keep the wings level. If you have enough throw and time it right the plane should pivot right around the wing spar.

Vertical spins. Get real high and cut the throttle, nose the plane over straight down and roll with the ailerons,, once it starts spinning give full rudder in the same direction as ailerons and the plane will spin so fast you wont believe it. Let off the sticks and pull easy on the elevator gradually adding throttle. Learn how to spin and then pull out3D variation is a blender.

Blender, be careful be sure you are comfortable pulling out if a diving spin 1st.
Get REALLY high, from level flight push into a dive and add right aileron and a little throttle (GULP!), after about 4-5 rotations give full down elevator and full left rudder at the same time. The plane should go to a flat inverted position and rotating around the prop spinner, As soon as it is flat inverted give it about 3/4 throttle and let the ailerons come to center, still holding full down elevator and rudder, throttle will stablilize the inverted flat spin and slow or even stop your descent. You will probably have to make small aileron corrections to maintain a "FLAT" spin. Once you get tired of the inverted flat spin just let off the rudder and fly out inverted or roll upright and fly out. If you hit it right it looks extremely cool, especially with a good bit of throttle. Just be sure to bail out of it at an altitude that you can get out of trouble at.

Wall,,,, haul butt flat and level and simultaneously give full up and chop the throttle, while trying to hold the plane straight up and down. The plane should go to a vertical attitude and come to a near complete stop like it ran into a "wall". Very cool looking, see the Yak video in the 68" Yak review at the top of the 3D message board.