There are two key functions to combat in World of Warcraft...
Character and Camera Control
These two functions interact and often conflict with one another for resources (namely your hands/fingers). Simply put if your left pinky is strafing left, it can't also be pressing the shift button or the 1 button. How you actually control your character will actually determine a lot about how you should set up your keybinds such that it minimizes the conflicts. Offloading additional tasks to the other hand is often an effective approach, particularly if the hardware supports it (i.e. a many button mouse like the Naga).
"In anything, if you want to go from just a beginner to a pro, you need a montage." /w TankSpot WTB Montage for Raiders.