I've been meaning to post these for quite a while.
I use a mod called grid combined with mouseover macros for all my major spells. Grid displays each player's vital statistics in a small box. In a 25 man raid everyone fits in about a 5" x 3" area. Using mouseover macros I don't have to click to target the person I want to heal - I just move the mouse a few inches and press a key. It's kinda like a game of "whack-a-mole". When some poor Marney crits and pulls aggro I see a red dot light up in his box and his health deficit bar starts growing as he takes damage. I can usually get a big heal on him unless he gets one-shotted.
I have seen a few occasions where mouseover bugs and I end up healing my target or myself instead. But with the old click and heal method I had plenty of times where I misclicked and healed myself too.
About 2 weeks ago while comparing builds I discovered I had this cool 41 point talent called Divine Illumination that I didn't have out on my bar. All spells at half mana cost for 15 seconds? That's gotta be awesome for conserving mana. I decided then that I would use macros to ensure I used it on every cooldown. And why not use my trinkets too? I always forget those too - or I'm too busy to hit the button when I need it.
Now I use downranked holy light and flash of light most of the time. When I need to whip out my big rank 11 holy light it's because someone took a massive hit and I'm probably going to be real busy and end up using a lot of mana. I started off with a macro that just cast Divine Illumination and rank 11 holy light. That was cool but why not make it a crit. I mean I'm casting it because I *need* a big heal. And why not toss in those trinkets too. Cool. But now I want to use this macro all the time as my only rank 11 holy light macro because I'm lazy and don't want to use another key on my N52. The cooldowns are all throwing errors and beeping and crap. I found a way to disable sound effects and clear errors and bingo a macro to cast holy light 11.
Rank 11 Holy Light#showtooltip Holy Light
/console Sound_EnableSFX 0
/use 13
/use 14
/run UIErrorsFrame:Clear()
/cast Divine Favor
/cast Divine Illumination
/console Sound_EnableSFX 1
/cast [target=mouseover,help][help] [target=player]Holy Light
Rank 7 Flash of Light#showtooltip Flash of Light(Rank 7)
/cast [target=mouseover,help][help][target=player]Flash of Light(Rank 7)
Rank 8 Holy Light#showtooltip Holy Light(Rank 8)
/cast [target=mouseover,help][help][target=player]Holy Light(Rank 8)
Holy Shock#showtooltip Holy Shock(Rank 5)
/cast [target=mouseover,exists,nodead][target=target]Holy Shock
Other mouseover macros:
Cleanse#showtooltip Cleanse
/cast [target=mouseover,help][help][target=player] Cleanse
BOP#showtooltip Blessing of Protection(Rank 3)
/cast [target=mouseover,help][help][target=player] Blessing of Protection(Rank 3)
*Edit*
Added a screenshot from VR that shows grid in a 25 man:
http://amangur.dkpsystem.com/viewpic.php?id=162