Bound 1-7, Q, E, R, T, F, G, Z, X, C, V, B + modifiers (Ctrl/Shift/Alt) - only using one mouse button (Middle) for mounting.
Feeling a bit cumbersome at times, but I have it set up this way since WotLK and I am, honestly speaking, terrified of even thinking of changing that.
The only reason I didn't buy Naga is the exact reason above - I would need to rebind everything, R.I.P. muscle memory.