Unless you have an amazing memory at remembering what keys are bound to what (I know I dont) I wouldnt go cross class boxing without one of these bad boys :
http://www.xkeys.com/xkeys/xkpro.php
The keys have caps on them which you can put the spell icons inside, this allows you to glance at the x-keys and know what spell you will cast without looking at the slave's screen and trying to read what key something is bound to.

Other than that Id say its just about making good macro's that allow you to get a decent damage spell rotation all by pressing 1 key.