Over the past few weeks I have talked to a few healers and realized perhaps not all our healers know how mana regeneration works and don’t have a strat to conserve their mana over the course of a boss fight. One thing you might want to consider is if you have a higher number of +healing gear it might be beneficial to use a spell that casts at least 2.5sec so you get your full +to healing (anything shorter then this you get a diminished return on your +healing) and cast lower ranked spells that cost less mana which increased your +healing ratio. I like to spam a very low cost healing touch spell that heals normally for 500-700 an I heal about 1100 to 1200 with it consistently. Now because this is a longer casting spell i always have it casting and i move if i don’t want it to go off to keep my self out of the five second rule if I don’t need to heal. 
For those of you that don’t know what the five second rule is, it is a 5 second period after the casting of any spell where you generate almost no mana from spirit. So by stopping my cast unless i need it to go off I gain a lot more mana over then next few second where I will be faced with the choice of casting or not casting again. 
Now if you are a healer that finds themselves in the 5 second rule a lot and don’t think you will be able to get out of it then mana over 5 second gear is for you. This gives you mana regardless of the 5 second rule (if you want it or not). 
I hope this post is helpful and I didn’t always have a casting strategy and didn’t always realize how all of this worked (so I thought I would share). So with all our new healers I just wanted to make sure that everyone understood this stuff. Give me a msg in game or ask questions here if you want more information about healing efficiency and practicality.