For those Grid and Clique users....

[Boboca]

For my healing is:
left click - chain heal
right click - riptide
shift left click - lesser healing wave
shift right click - healing wave
scroll down - water shield
scroll up - earth shield
scroll left - heroism
scroll right - clense
ctrl left click - player menu
alt is the focus mod. button

[Migage]

Everyone's own playing style/mouse use changes comfort levels, I guess it's just playing around to you find one that works.

For me, liking to keep Left and Right mouse-clicks open (and also was unaware that you could make Clique on work on Raid frames).

Shift Left: LHW
Shift Right: HW
Middle: CH
Shift Middle: Riptide
Ctrl Left: Cleanse
Ctrl Right: Purge
Kbrd 1: WS
Kbrd 2: ES
Kbrd 3: "OhCrap" Single Target
Kbrd 4: "OhCrap" Chain Heal

[Radux]

Left Click: LHW
Shift Left Click: HW
Mouse 4: CH
Shift Mouse 4: Riptide
Mouse 5: Cleanse Spirit
Shift Mouse 5: NS + TF + HW
1: NS
2: TF
3: ES
4: WS
5: Troll Racial (Berserking)

[Eikons]

Left: LHW
Mouse3(scroll click): Riptide
Right: CH
Mouse4(Thumb): Cleanse

Shift+Left: HW

1: Trinket+TF macro
2: NS
3: ES

Don't use much else besides that, mainly just mouse1, 2 and 3.