I use feint, clutch kick, powerover, shift-lock (when downshifting) and clutch drop (while upshifting) the most. Those are probably the easiest to learn.
I'm 5'10" and i have very long legs, and i wear a siza 10 1/2 shoe and i have trouble with heel-toe. My knees hit the bottom of the steering collumn and my shoes hit the wrong pedals.