I like to keep it simple when I'm healing. I have Xperl unit frames and Bartender 4, I have a couple of macros that I use in 5/10/25s. I have GH, FH, and CoH on mouseover macros so I can just move the arrow over the person I would like to heal and hit a key cast it on them. This allows you to heal anyone in the raid without losing the main target. I also feel that a self shield macro is a life saver in raids. I can't count the times where I have either died, shielded the tank by mistake, or was unable to get heals off in time on the tank because I was taking aoe dmg and had to deselect a target in order to cast my shield on myself.
/cast [target=yourtoonsname] power word: shield
/cast [target=yourtoonsname] renew
/cast [target=mouseover] greater heal
/cast [target=mouseover] flash heal
/cast [target=mouseover] circle of healing
For people who do not enjoy managing lots of addons and like to keep it simple, these five macros are great :)