For Restoration and Balance druids, mana is all-important. Without it, we're reduced to smacking things futiley (or, in the case of our owlbears, semi-futilely) with our weapon or tree-fists. And as mightily powerful as you think your tree-fists are, there are more useful and important things you could be doing. Therefore, it's important to learn as many ways as possible to keep your mana up. Hopefully, this should help, and if I'm missing anything, I'm counting on my limited reader base to help me fill in the gaps. Phaelia also recently added an article on the same subject, and I would encourage you all to go read it, as she has the math to back it up and I didn’t say everything she did. It would feel like plagiarism! However, I did add a few things she overlooked, especially as I am looking at this from both a Balance and Resto perspective.
Moonglow – This talent reduces the mana cost of your Moonfire, Starfire, Wrath, Regrowth, Rejuvenation and Healing Touch spells by 3/6/9%. Moonkins are especially mana-pressed (hence the derogatory term “Oomkin”) so any reduction on cost is helpful. Since it works with three healing spells as well, it is also good for Balance/Resto hybrids.
Dreamstate – This talent allows 4/7/10% of your intellect’s worth of mana to regenerate constantly, even while casting. This used to be the defining talent of the popular Dreamstate healing build, but now it is used mainly by Moonkins, with Restos favoring the tree healing specs.
Moonkin Form – This form allows your mana to regenerate from successful melee damage. Make sure to have an AP staff on macro equip for when this becomes necessary (I recommend the Cenarion Expedition Exalted rep level Earthwarden, or, if PvP is more your style, Twalkins/Twalvanis of my guild recommends any of the Gladiator's Maul variants).
Natural Shapeshifter – Reduces the mana cost of all shape-shifting by 10/20/30%. This is a must for all feral druids, and is handy for anyone who knows how much shifting forms occurs in arena. Is also welcome for when you are forced out of form to decurse or abolish poisons (depending on your form at the time). However, due to the abundance of other talents in the restoration and balance trees which are more readily available, it may be wise to skip this unless you are a raid healing 1/0/60 or 0/0/61 spec.
Intensity – Allows 10/20/30% of your mana regen to continue while casting. Every druid, no matter spec, should consider this talent (it has bonuses for ferals as well) as it is remarkably powerful.
Tranquil Spirit – This talent reduces the mana cost of Tranquility and Healing Touch by 2/4/6/8/10%. This may not be worth taking, however, if you are not a 0/0/61 or 1/0/60 raid spec, as Healing Touch and Tranquility are highly situational.
Living Spirit – Increases your total Spirit by 5/10/15%. Since Spirit is connected with mana regeneration, this is another helping hand on the way to keeping your mana pool available to you.
Tree of Life – Though this form limits what healing spells you can cast, their cost is reduced by 20%. This form should be used wherever mobility isn’t an issue, due to the 20% movement speed decrease.
Lower City Prayerbook – Though this is only helpful for restoration druids, it decreases on use your healing spellcast costs by 22. Now, this may not look like a lot, but with five casts of Lifebloom within this 15 second timer, you have already saved mana equivalent to one free Lifebloom. And with its nice bonus to healing, this is an all-around good trinket.
Pendant of the Violet Eye – Most people are raiding at least into Kara these days, so I don’t see this as too high a goal to consider unreasonable (drops from Shade, one of my favorite boss fights). This pretty trinket, though having no “equip” effect, on use will return you 21 mp5 per mana-costing spellcast for its 20 second duration. Of course, you have to remember that as soon as the 20 seconds are up, all that mp5 disappears, so your spell cast speed should still slowdown a bit to take advantage of this ability. As it only has a two minute cooldown, it is good to use this trinket whenever it is available. And since this operates on mp5 and not on spirit, pairing it with your innervate will give no special bonuses.
Bangle of Endless Blessings – Phaelia over at Resto4Life wrote an in-depth article describing how best to use this particular trinket. Its on-use ability increases the wearer’s spirit. This works well with innervate, which increases your spirit-based mana regen by 400%, and 100% while casting. Couple with a high-spirit weapon to switch out and your mana will boost rapidly. Its equip ability is handy as well when it procs.
Dark Moon Card: Blue Dragon – This allows, on a 2% chance proc, with each spellcast to gain mana regeneration while casting. This is a good trinket to have if you are strapped for mana or an anticipating a long fight. Without an equip use, however, it is slightly weaker than a trinket with straight mana regen. Natural Perfection's Aftereight wrote a very nice article about it.
Party Members You Love to Have
(Retribution) Paladins – You’re maybe thinking “What?! Who uses ret pallies?” Well, my guild does. We also use prot pallies. And, you know, a holy pally. Somewhere. He’s lazy. But having someone with judgement around is spectacular, especially if they’re the obliging sort who will judge the mob with wisdom to return mana to whomever smacks it with a stick. They also bring lovely blessings which boost your mp5 dramatically. However, as a boomkin, you may want to forego the Blessing of Wisdom in favor of Salvation. Any pally can give you blessings, however, so that is why ret is in parentheses. The more pallies you have, the more blessings, though you cannot get two BoW.
Shadow Priests – Oh, how I love thee. Their special abilities return health or mana to the party, easing up your job in one way or another. There’s hardly ever a reason to not want them around.
Feral Druids – Specifically, ones not tanking (though we love them, it is not in the same way as pertains to this article). As ferals, they don’t especially need their innervate, nor will they be wearing gear to capitalize on it. Often, they don’t mind shifting from kitty to pop one over to a druid (or priest) who asks. If they are a tank, an option is for them to throw an innervate on you right before pulling. This does waste some mana you could gain from that innervate, but shifting out of bear form mid-fight is suicide, and that is mana you would not otherwise have. My tankbear does it to keep me from drinking between fights. But he’s impatient.
Mages – Arcane Intellect increases your intelligence, which increases the size of your mana pool. The larger your mana pool, the more you have to play with. Also, they bring these nifty little tables with delicious biscuits.
Holy Priests – These priests have a spirit buff. This is excellent, as druids are spirit-based mana regenerators, and innervate is based off of spirit.
(Resto) Shamans - I totally did not forget them so Mahndo has no reason to be upset at me. Right? Right. On with the explanation part. Why does everyone love Shammies? For the totems. Shamans can drop mana spring totem, which gives 20 mana every 2 seconds (at the highest rank) to anyone in the party within 20 yards. And restoration shammies have the talented mana tide totems, which don't live as long but restore 6% mana every 3 seconds for 12 seconds (total of 24% mana).
Lesser Known Consumables
Major Dreamless Sleep Potion – These are highly situational, for moments where you only have a brief rest. Used judicially in boss fights, they return more mana than you would get off of a regular super mana potion, with health returned to boot. But you are out of commission for 12 seconds and if the sleep is dispelled you stop regaining mana. Before using these potions it is recommended you announce it, and scope out a fight prior so you are aware of your time constraints. I personally found them handy while chasing after Thrall, the noob in the leather gear who charges into mobs without waiting for the healer’s mana and rides a horse in such a way that travel form outstrips it. No wonder he couldn’t escape.
Fel Mana Potions – For this potion, you really need to read this article. (Yes, I link to Resto4Life a lot. That’s because she knows what she’s talking about.) Their nasty debuff effect can easily be cancelled out by making sure your base healing/spell damage is high enough to buffer it, or by drinking an Adept’s Elixir (for Balance) or Elixir of Healing Power (for Restoration).
Demonic Rune – This must be carefully used as it does hurt you for a possible 600 to 1000 health. Its return, possible 900-1500 mana, is light, and is best used for shorter fights where you are in negligible danger and your pots are on cooldown, or you don’t want to waste them (though traveling with downgraded mana pots is also recommended). Since they do not share a cooldown with potions, they can be handy for emergencies in boss fights when everything else is on cooldown. They can be farmed easily from the satyrs in Felwood but are Soulbound, so you must do it yourself. This is easy for even a Restoration druid as they require only one or two applications of Moonfire apiece. They can also, in an emergency, give you a durability-loss-free kill, as if you can time it so you kill yourself with one of these it counts the same as if a pally DI’s or a lock hellfires to death. Please, however, wait to make sure it's going to be a wipe before suiciding.
There. It's a bit short, I'm aware, but, like I said, I don't like repeating what other people have said, especially when they get to it first. I'd shake my fist at Phaellia if she wasn't so darn helpful and informative and nice and stuff.
I hope this helps, though it is by no means complete.