For buffs, get the SmartBuff addon. On each toon configure SmartBuff to cast the appropriate buffs, and set the keybinding.

Then all you need to do is mash the SmartBuff key a few times and all your toons will cast whatever buffs are needed by the team. SmartBuff will also warn you when buffs are running out, so you'll never forget to buff.


As for healing, I operate a focus-based system, where my slaves always focus on the leader. Then, my healing macro on my slaves is something like this:

/cast [target=focustarget,help][target=focus,help][] HealingSpell

i.e. which will try to heal whover my leader is targetting (if it's friendly), or my leader if he has no friendly target, and if I have no leader (i.e i'm soloing the toon), it will heal whoever they have targetted.