So there are many different ways to heal as a druid. Pretty much it depends on what your assignment is.
Raid healing: For the most part a druid will always be on the raid. Only in extreme circumstances will a druid ever be on a Main tank.
This consists of throwing out Wild Growth on every cooldown and casting Rejuvenation as much as you can within the WG 6 second cooldown. Every now and again if someone does not get a bigger heal from a priest of shaman you can throw a Nourish up.
GLYPHS
Glyph of Wild Growth
Glyph of Nourish
Glyph of Swiftmend
With these, your WG hits an addition person, if you need to quickly heal someone, Swiftmend can be used without taking off a HoT and Nourish also heals for extra when there are multiple HoTs on a player.
If you are MT healing, which should be rarely, throw up all your HoTs and then Nourish spam until you need to refresh your HoTs. Lifebloom you do not really have to use, just Regrowth, Rejuventation and Wild Growth.
I did not do the math to prove this, but I find this healing method to be effective.