If you're WARing, you can save a couple button slots by swapping (Fell Cleave and Decimate) or (Inner Beast and Steel Cyclone) onto your bar whenever you change stances.

/ac (Defiance)
/chotbar set (Inner Beast) __ ___
/chotbar set (Steel Cyclone) __ ___
/micon (Defiance)

and

/ac (Deliverance)
/chotbar set (Fell Cleave) __ ___
/chotbar set (Decimate) __ ___
/micon (Deliverance)


Type
/? chotbar
in game for details on the /chotbar command.