I use the first 2 rows only (3rd one only have tanking stuff...i often don't even equip those skills). I try to leave similar skills close and bloodbath in the middle for fast access.

L1: Heavy Swing, Skull Sunder, Bloodbath, Storm Path Foresight, Fracture, Sacrifice, Cure, Second Wind, Barbs (the last four i never change. They don't even are part of any macros)
L2: Maim, brutal swing, Disorient, Brandish, all 4 aborsb, the 2 siphon

You can see that similar WS are aligned so, if i have one WS i need during recast still i can just tap down and use the similar one.