Healer tips and shenanigans:
1. Feat.
So, first thing is get the Healer feat NOW. It scales up, so it’s always good, but it is SO powerful at low levels. Buy extra healer’s kits to power it. (10 uses per kit, so 2-3 should cover anything during an adventure. Remember to replace when you use one up. They're cheap.) Don’t forget that in addition to its big heal (1 per SR per target) you can use a kit for stabilizing someone to 1hp which means they keep fighting! HUGE. Another great one when you get your next ASI is Inspiring Leader which gives BIG temp hps to your buddies, refreshable every short rest.
My recommended healing feat sequence is 1. Healer 2. Inspiring Leader. 3. WIS+2 up to 20.
2. Race.
Any race with a +1 or +2 WIS is an obvious choice. Including Human and Half-Elf. Aasimar (Protector) has a little extra healing add but it’s daily. Consider using a Human(variant) to get the Healer feat if less than level 4, though if you play level 5 at a table you’re Human forever so Be Ready. If you want a different race than Human, an alternative is to go 4 levels into Cleric (or other) and use the ASI, but you’ll drop some low-level effectiveness. What am I talking about? Read on.
My recommended healing feat sequence is 1. Healer 2. Inspiring Leader. 3. WIS+2 up to 20.
2. Race.
Any race with a +1 or +2 WIS is an obvious choice. Including Human and Half-Elf. Aasimar (Protector) has a little extra healing add but it’s daily. Consider using a Human(variant) to get the Healer feat if less than level 4, though if you play level 5 at a table you’re Human forever so Be Ready. If you want a different race than Human, an alternative is to go 4 levels into Cleric (or other) and use the ASI, but you’ll drop some low-level effectiveness. What am I talking about? Read on.
3. Sorcery points and metamagic add flexibility.
Cleric + Sorc is amazing. Uh. Maze. Ing. Add the metamagic to your healing spells. Twinned healing word or cure wounds = PROFIT. Only have one 3rd level spell slot left? Turn it into sorc points and back into 2 or 3 level 1 slots. Quicken spell makes your casting time a Bonus Action which you can use alongside healer kit, or dodge, or whatever action suits you. BESIDES, you gain some effectiveness with sorc spell options and even cantrips that will scale up. The Shield spell adds to your already-decent AC. Or grab utility spells. Or if you’re human, free Light cantrip, right?
Find Familiar to deliver touch spells? (Personally, I find this just a bit too much cheese so I avoid it when I'm playing. But I play armored healers. YMMV.) Take a couple levels in sorc, or maybe 3+ if you find spells or one of the paths interesting. (Important: As long as you ONLY drop in 3 levels you will literally lose no access to any spells. Drop 4 levels and you lose 9th level spells. Does it matter? You decide.) Find Familiar normally seems a waste for a sorc spell, but the other option I'd recommend for a familiar is Magical Initiate feat. Now you're waiting 3 levels for it, competing it against Healer Feat and Inspiring Leader.
One word of warning: You can never have more sorcery points than shown on the table for your (sorcerer) level. So if you're only dipping 2 levels, 2 points. What's the impact of this? You can never use Heighten because it's 3 points. (so what?) You can't Twin spells over level 2. (who cares?) You'll spend a lot of bonus actions refilling your 2-point pool during battle. (ugh, but tolerable) You will be unable to convert higher-level spells to increase the number of cure spells. (SERIOUSLY PAINFUL.) My Cleric-sorc is a primary sorc, so I don't worry about this limitation.
4. Rogue (Thief) shenanigans with healer kits.
So let’s say you want to use healer’s kit as a bonus action in addition to whatever spells you cast. Drop 3 levels into Rogue (Thief) and Use Object becomes a bonus action. BAM! Plus you can look into other objects like alchemists fire, caltrops, bearings, acid… And take roguish expertise in a couple skills- maybe Thieves tools so you can pick locks with Guidance, or Perception, or… And also you get backstab 2d6. Err, sneak attack. Anyway, nice.
5. Life as a Cleric.
Life cleric is fabulous for a spell-based healer. Even 1 level. Every healing spell you add 2+spell level + WIS mod. That’s EVERY healing spell, even Goodberry if you get your hands on it somehow. (See Bard, or Magical Initiate feat (Druid or Ranger)) Plus at level 2 your channel divinity burst heal 1/SR, but take note- it can restore a creature to no more than half of its hit point maximum. I've seen many people ignore this limitation, but that would be wrong. Don't do it. Keep it honest- the tips on this page are more than you need; cheating is not necessary.
6. Bards bring it, too.
Bard is awesome with song of rest. That plus Prayer of Healing from a cleric = short rests that heal a LOT! Lore Bards at level 6(?) gain 3 spells from wherever. Goodberry as mentioned previously, Aura of Vitality should just not even be legal to take since it’s a level 3 PALLY spell intended for much higher level use, and… what for the 3rd for a healer that you don’t already get as a bard… Not sure offhand. So, be ready to sink a lot of levels into Bard if you go that route, but on the plus side they get the main healing spells up until resurrection.
7. Druids?
Erm, maybe. Mostly I see animal druids, but summoner/healer would be an effective combo. They have the basic healer spells but lack the Life Cleric or Bard / Lore Bard extras. Adding in Conjure Animal 3rd level spell IIRC adds free damage spongery that doesn’t need to be healed, more targets for your opponents to strike, and also adds extra damage output. Not a traditional healer concept but gets the job done.
8. Crown Paladins (from SCAG) do some healing based on Channel Div, but because if’s driven by CD it’s a bit too use-limited for my tastes.
9. Any healer (bard, cleric, druid)
After you get the MASS healing spells things change. If you can get the party to spread out damage, your efficiency spikes. They all get it. The other game-changer is Heal for 70 points a shot, but as a 7th level spell, you need to plan for it AND if you’re going through it as a cleric then you need to travel through the wasteland of 6th level cleric spells. AND you don’t get much of them per day. 2, or 3 if you burn your 8th level slot. Of course 9th level brings Mass Heal, I think that’s depending on your class. Basically due to the differences between levels 1-5 and 6-9, your bread-and-butter heals are the level 1-5 spells.
10. Warlock shenanigans.
Warlocks recover their very few slots every short rest. You can use this to big advantage to cast Many More healing spells than normal per day, at the cost of dipping some levels. The other class benefits could help too, like invocations Devil's Sight to Healing Word see into darkness, fog, smoke, etc. ("A creature of your choice that you can see within range...") , Fiendish Vigor for personal temp hps, various Warlock spells like Hellish Rebuke, Misty Step, etc.
11. General strategy.
Keep your buddies up in battle by bringing them up after they go down. Use bonus actions and twinning for double-whammy healing. Who cares whether they have 1hp and will go down again for more healing, 25 and might be OK for a few rounds, or 85 and can take several big hits. If they had 1hp and absorb 60hp and go down, that’s 59hp you don’t need to worry about on someone else.
Do you want to supply between-combat healing? I don't, other than my healer's kit. Everyone has hit dice for a reason. Bards get to use Song of Rest. Prayer of Healing is nice if you must. But not ever, no how no way, would I ever top off the party between combats. Save your healing spells for when people go down in a fight. However, your healer's kit usage recharges during a short rest, so burn through whatever charges you can. (Remember, it's limited to one heal per person until your next short rest.)
Do you want to supply between-combat healing? I don't, other than my healer's kit. Everyone has hit dice for a reason. Bards get to use Song of Rest. Prayer of Healing is nice if you must. But not ever, no how no way, would I ever top off the party between combats. Save your healing spells for when people go down in a fight. However, your healer's kit usage recharges during a short rest, so burn through whatever charges you can. (Remember, it's limited to one heal per person until your next short rest.)
First, don't worry too much about the massive damage Giants put out. Were you on the front line? No? GOOD you don't belong there unless you specced for it. And, if YOU drop as a healer, make sure every bastard in the party (yeah I called em bastards- they let their healer drop, so they are sucky bastards!!) knows up front about that emergency potion of healing you keep in your pouch. (You know, the one you bought between last session and the next one for 50gp.) And tell them to administer it to you, so they DON'T DIE. If you have a pally or ranger or druid or bard they can also help your ass up with a Cure Wounds.
12. Class/level recommendation, and the maths at the end.
FIRST OFF: don’t play ALL of these options. You will get BORED because you heal so much that your party walks all over everything. Pick a couple and you’re AWESOME. Pick three and you’re SUPERAMAZINGCOOL and people you meet at cons will beg you to play at their table. Use four and you will WIN AT D&D.
So, what class breakdown? What’s your main class? Maybe cleric. Maybe bard. Maybe sorceror! Maybe druid? To hit each classes healing stride:
Cleric 2+
Sorceror 2+
Bard 2+ for song of rest, or 6+ for Lore spells.
Druid 5+ for summon
Rogue(Thief) 3+
Let me math the Healer feat in case the uberness was not understood:
Straight cleric/bard/druid/ranger: Cure wounds 1d8+3, as higher level (AHL) = +1d8. (When you use ASI for +2 WIS this changes from +3 to +4, and your save DCs go up one. If you're really devoted to healing, you shouldn't usually be casting spells on opponents.)
Life cleric: Cure wounds 1d8+3+2+1, AHL = +1d8+1. IF you use AHL the majority of your static does not increase and you lose 5hp. You can sometimes twin this for 2 heals, 1 sorc point.
Life Cleric Healing word: 1d4+3+2+1, AHL= +1d4+1. At range of 60! You can almost ALWAYS twin this. In fact I would hold off use until you CAN twin it.
Healer feat (big heal) = 1d6+4+target level. We're level 5, so 1d6+9. As action. One per target, per Short rest. Pay attention, SHORT. When you need a healing recharge for battle healing mid-day, this is your ONLY option after spells are gone. Because your spell slots only come back after LONG rest, unless you're using Warlock shenanigans.
Healer feat (stabilize) = 1hp. That's enough to fight as a glass cannon. At level 5 offense is pretty strong at 3 attacks, and if you get hit for 30 then you take that extra 29hp and throw it away because you're still at 0. It's 29hp you don't need to heal.
