A big part of it, will be deciding on a logical set of binds.
I had every druid cast at any target of the Grid frame.

My default heal was Rejuvenation (on a left click).
This, with five Druids was very good healing for most targets most of the time.

My binds, which took a while to learn, are:
- Left Click: Rejuvenation
- Alt + Left: Nourish
- Ctrl + Left: Lifebloom
- Right Click: Cleanse Spell
- Alt + Right: Healing Touch
- Ctrl + Right: Regrowth
- Scroll Wheel Up: Swiftmend
- Scroll Wheel Down: Wild Growth

Learning them took quite a while, but the process was relatively easy.
Play with one or two clicks initially, and once that is comfortable add another click and use that often even if its not always optimal.
With the goal of gaining the "muscle memory".




Some useful combinations for me:
a) Left click whoever is taking damage = Rejuvenation (a HOT effect, and fairly strong heals)
b) Scroll Wheel Up = Swiftmend (requires a HOT, instantly heals a large amount, creates an AoE Efflorescence around the target, healing everyone for a lot)
c) Scroll Wheel Down = Wild Growth (multi-target heal, picking the most hurt first automatically)
This combination was extremely nice, anytime my team was focused; if the horde did not use Crowd-Control effects, I could easily outheal the damage of a dozen players.

My Alt clicks are: Efficient uses of mana, with Left being faster and Right being larger.
My Ctrl clicks are: Emergency healing that eats the mana, with Left being "now" and Right being larger.




Major cooldowns are:
- Innervate for extra mana; for optimal use Glyph it, and have each Druid target the next Druid.
- Tranquility on round-robin... huge AoE healing, especially if you spam it 2-3 times... on a relatively short (talented) cooldown.
- Tree of Life... with lots of benefits.
---- Wrath is extremely fast and hits harder, while this is up; even with just Honor gear, I could down 4-5 targets from range in one Treeform cycle.
---- Lifebloom is not restricted to a single target, so at the cost of LOTS of mana, everyone can have the burst healing.
---- Regrowth is an instant cast spell; I had this glyphed to auto refresh the HOT portion on anyone really hurt.




I did not really bother with the Roots, which could be an improvement.
I had a Rebirth macro, where each Druid attempted to Rez another in a sequence:

On A:
#show Rebirth
/cast [@DruidB,dead][@DruidC,dead][@DruidD,dead][@DruidE,dead] Rebirth

On B:
#show Rebirth
/cast [@DruidC,dead][@DruidD,dead][@DruidE,dead][@DruidA,dead] Rebirth

Putting the option to Rebirth, as a round-robin Grid click might be strong.
You could have allies "pop" up at full health (Rebirth Glyph) as they fall.
And with Innervate also on round-robin, you could give caster allies (other heals) immediate mana on a Rez.