On festergut one of the most effective uses of a resto shaman is bouncing chain heal off the melee. Just spam it on the melee when fester doesn't have many stacks of inhale blight, and you will do sick amounts of healing.
Lesser Healing Wave is your spot healing tool, and it's great on fights where random, people take relatively irregular spikes of damage. Stuff like the Shadowbolts on Lady Deathwhisper - those are great candidates for lesser healing wave.
I am by no means a great healer (I don't think), but what I have learnt from experience is that healing is much more about picking the right tool for the job than dps or tanking is, where you pretty much just spam the most effective sequence of buttons. Knowing the fights well is key. Darieth is right though, as a shaman if you are assigned to raid heal, on most fights chain heal will be a MASSIVE portion of your overall healing.
On my shammy when I raid healed on Toravon in VoA 25, I pretty much cast riptide and funnelled chain heal through it, and those were the only two active heal buttons I pressed, the rest just came from chain heal and earthliving procs, with some ancestral awakening thrown in for good measure.
Generally though, meters can be a very poor guidance for new healers, especially from healers who are used to looking at damage meters as DPS or tanks. The more healers you take, the lower everyone's HPS will be, if some healers are stupidly fast, chances are they will snipe your heals.
Getting a good set of raid frames is a must. On my druid I have Vuhdo setup to show me who has Power Word Shield on them, and this is a serious boost to your effective healing. Essentially, on fights with alot of relatively constant damage being thrown around, prioritise your heals on people who DON'T have PW:S on them - they will need it more urgently than people with some overpowered 14k absorbtion shield on them, and yes, disc priest shields really can get that powerful (and more) thanks to amazing gear and the hilarious ICC buff.
Get a method worked out - many disc priests start at the top of group 1 and work down the raid that way, moving down grp 1 from top to bottom then moving onto grp 2 etc. As a druid therefore, on fights with constant damage auras like Lanathel, I start hotting from the top of group 5, and working backwards, meeting the disc priests in the middle. This means that groups 1 and 2, and some of 3 have shields absorbing damage, while damage being taken by group 4, 5 and the other part of 3 is being healed by my hots.
Cooperation is key in 25 man raid healing - DPS often try to compete with each other to get higher on the numbers etc, but if there is anything I have learnt from healing so far, it's that healing is one of the most teamwork reliant aspects of the raid game - you need to communicate, you need to understand how the other healers work and cover for them.
Healers are like a big cuddly happy family of love and green numbers!
Origin ID: Slashylol
Steam ID: Wargod37