Excellant! wish there was more!!
I was trying for some tubes this weekend and was having trouble staying high on the face. I realized that I wasn't dragging a fin, and when I did it helped me stay a bit higher before sliding out. I think if I push on the outside of the mat while leaning on the wave side of the mat this will increase the amount of hold the mat has and will keep me higher on the wave. Does this sound right?
You are on the right track. This link might help. http://magictowelride.blogspot.com.au/2012/12/a-tube-riding-masterclass-with-mt.html