You can use mouse over macros for your single target heals. The macro should only contain one action line surch as :
Code:
/micon Physick
/ac Physick <mo>
And that's about as useful as macros get. You can't use multiline action macros as there is no guarantee on the execution order of each line. And you shouldn't macro anything else (especially not dps skills) for the reasons posted by the previous comment. Single target heals are the exception because you won't use them often enough to impact you in any meaningful way.
If you mouseover you can just keep your ennemy as your target and not worry about swapping targets to heal. So there's a significant advantage there.