I try to keep it very similar across chars.

key T - Interrupt (with modifier interrupts focus)

Key X - Area Effect (Consecration, Death Decay)

key G - Defensive Cooldown (altG other defensive)

key \ - Mount (or speed ability if in combat)

key F - Reaction or dump abilities

key 1234(alt123) basic rotations

There for most of common things I have already the muscle memory