I know a ton of people know how to do this by now. However, there are still a decent number of folks in the community who aren't efficient, haven't tried this, or are just looking for ideas. Either way, in the worst-case scenario this may help the community by familiarizing more people with the content and giving us a larger draw of quality players for pickup groups. While pickups aren't too common on Aegis (most people have settled into shells or specific groups) I still see a couple everyday.
I am going to write this from the perspective of someone who is just learning the battle but has some limited familiarity with it. I am going to try and keep it pretty succinct, as well but still thorough enough to explain it all. In addition to this, I will also explain some important things that are common misconceptions. I have successfully done this a number of ways at all locations with a number of groups so this is a culmination of many experiences and observations. This is also assuming the common build of TANK, WHM x 2, DoH x 3, and DoL x 2. This can be done a variety of ways but this is the most common where I am.
Lastly, the biggest (and lengthiest) portion of this is about the DoH and that's for good reason - people don't understand their role as the main DD in hamlet.
Tank Perspective
Your main job is to kill the two "animal" mobs that pop and then kite the main NM. You will also be claiming the zombie. Maps are provided so you can see where they pop. After the second "animal" is killed you will kite the NM AWAY from the attacking NPCs. Keep in mind that whenever the NM issues enemy orders you will lose hate for a second - this is when you flash/voke/etc. to get him back.
Hyrstmill
Golden Bazaar
Aleport
Outside of that you can choose a couple of roles. The first being that of voking mobs off of DoL/DoH and running them into archers. Personally, I dislike this and I will tell you why: it occupies archers and messes with the rhythm of the DoL/DoH.
The second is one that I have really become fond of and contributes to faster, more efficient runs: ripping the HP down on mobs (special mobs, especially.) You don't kill them but you certainly contribute to their death. The main idea is to take the mobs down to about 15-20% (shy away from AoE WS) and then let the archers polish them off. This greatly thins the numbers and prevents buildup. You will lose hate frequently but every 10% you whack off (giggity) a mob it's just money in the bank.
Notes about 2nd "animal" mob: This will pop around the 20 minute mark and you need to be there claim it ASAP and then zerg it down. The NPCs will not help with the "animal" mobs or the zombies. When this mob pops the NM will be right behind it and you need to get hate immediately while still killing the "animal" as quickly as possible.
Notes about kiting NM: Pick a path where attacking NPCs aren't prevalent. Also, don't DPS the boss down because if it dies before the zombie you are SOL. With poison being up frequently you are going to need to manage hate via job abilities. Again, remember that you will need to get hate back immediately when orders are issued. For this reason you need to manage your timers, as well. As the mobs thin out you will need to claim the zombie (it pops after all regular mobs aside from the NM are killed). This really isn't a problem since most kiting paths place you at the spawn. Also, because of a lower DPS and better survivability I prefer a PLD tank.
White Mage Perspective
This is surprisingly easy to play inside the instances. Your main job is to keep the NPCs buffed and popped with regen. You will also have to occasionally prop the tank up, too but it's his/her job to let you know where they are and how soon they will need it. You will also sometimes need to cast Esuna on a DoH/DoL but again, it's up to them to get near you and let you know. Don't burn buffs on them or cures (unless absolutely necessary) - a regen will suffice and it isn't even needed for DoH unless they are <50% health since they recover this while crafting.
There are a couple of ways to do this. The first is to divide the map between front and back and then assign a mage to each section. The second is to have the mages roaming and going where they need to. Personally, the obvious and best idea is to merge those two concepts with each mage picking an area to cover and then transitioning to help each other when possible.
Outside of this you will need to help nuke down the "animal" mobs along with regular ones. Remember to manage MP and get off the mobs around the 15-20% mark (animals are the exception.) If you are buffing and using regen primarily (cures, sparingly) then MP shouldn't be an issue. Some parties will ask you to claim the zombie mob and some will not. In all reality the tank should be kiting the NM near the spawn or at least on the way to it once the final mobs are dropping. You will need to help kill the zombie ASAP.
The last thing that I need to cover are the enemy orders. There is an orange box that will appear over one of the four icons in the top-left of the screen - this is where the enemies are targeted. When this goes off you absolutely need to be there and focus on keeping that NPC up until the orders have been reset.
Note on frontline NPC: There is always one frontline NPC in each zone that takes initial hate and therefore just gets raped. Know where he is and also be ready on the final wave around the 13:20 mark to be ready to curebomb him if things aren't going perfectly. This final wave carries the biggest hitters of the instance and it pays to be prepared - think about having the second white mage up there to help if it's possible.