My setup is as follows, using a gaming mouse with 6 mouse number keys. I currently set things up so that most of the oGCD skills are on the mouse for easy weaving, and main combos are in easy to access places. Jumps/Limit Breaks/AoEs are on "harder to reach" buttons because they are less common and I should have time between using them to re-position my hand.:

Main Combo
1 - True Thrust
2 - Vorpal Thrust
3 - Full Thrust

Buff/Debuff
4 - Heavy Thrust
5 - Phleb

Emergency
6 - Mercy Stroke (oGCD)
7 - Bloodbath (oGCD)

Second Combo
Q - Impulse Drive
E - Disembowel
R - Chaos Thrust

oGCDs
M1 - Leg Sweep (oGCD)
M2 - Jump (oGCD)
M3 - Blood for Blood (oGCD)
M4 - Life Surge (oGCD)
M5 - Power Surge (oGCD)
M6 - Internal Release (oGCD) (I currently have Doom Spike here)

Jumps
Ctrl+1 - Elusive Jump (oGCD)
Ctrl+2 - Spineshatter Dive (oGCD)
Ctrl+3 - Dragonfire Dive (oGCD)

Limit Break
Ctrl+5 - Limit Break

AoE
Shift+1 - Doom Spike
Shift+2 - Ring of Thorns