NOW UPDATED FOR TBC! :) Click here to find out how to to chain trap a mob multiple times, but beware of diminishing returns!
The alternate title for this was Zen and the art of chain trapping. My diagrams show the pulling from a hunter's perspective, but a tank can also pull so long as he or she knows where the traps are.
Basic rules of chain trapping:
1) Communication - Let people know you're going to be doing this. Most people don't know that hunters can cc more than one mob, or one mob multiple times.
2) Don't start with a sting - Sometimes the mob you aren't expecting to run into a trap runs into a trap
3) Be prepared for the worst - Some mobs are immune to ice cubes, some mobs resist them, some people see the big ice cube as something that must be hit.
4) Your pet is your best friend! - Outlands elites hit freaking hard. If you are chain trapping, your pet can save you or a healer.
5) As cool as it is, misdirection can prevent you from chain trapping because all the aggro goes to ye olde tank instead of to you. Just know your threat limit and peel off one mob if you're misdirect pulling.
OK, so here's one way to chain trap
First, my legend. You are the happy face. your tank is an angry face. Everyone else is staring in wonder at your leet trapping skills.
The mobs are represented as evil red dots of doom
Shoot the mob at the back* with a concussive or Silencing** shot. The other mobs will come running right for you, this guy will be slowed - and he will be the one you lure into the SECOND trap.
* Only hit the rear mob if you can pull it without aggroing everything else or pull it after the tank has pulled. When I'm tanking, I mark a rear mob for the hunter, unless the hunter requests otherwise.
** SIlencing shot pulling caster mobs is sexy. If you Silencing Shot pull, do NOT concuss the mob or it may stop to cast before it hits your trap.
If your trap cooldown is up, you can lay another trap and lure the concussive shotted mob into it!
Rock on.
Run around to make sure the mob is aimed right at your second trap, and voila. Two mobs on ice.
You have two less mobs to fight. Huzzah!
You can keep placing traps every 30 seconds so you can keep chain trapping indefinitely. That is, until diminishing returns kicks in.
But wait, there's more
"I want you to chain trap the blue square, please!"
Only 2 really tough mobs? or does your tank want you to control ONE mob in a large multi pull? No problem. Set up a trap right next to the trapped mob. As soon as it pops, the mob will be refrozen.
It's good to do this away from the rest of the group, but you must stay within range of the DPS target. This means that your mob is usually behind the main group.
If you have to chain trap one target over and over you MUST know how to kite or make sure your pet is able to pick up the mob when it untraps so it doesn't come and one shot YOU.
Because you will have your mob controlled AWAY from where the action is, if you run into trouble, try to get into intervene or intercept range and your tank (Who is keeping an eye on your health bar. Did I mention I love hunters?) will come and taunt it off you.
Healer's best friend
As an alternative, you can also run to the healers and pop an ice cube in front of them. In fact, I have saved many a healer this way by diving in, feigning and trapping after they've caught aggro and the tank(s) are swamped. Even if the cube is broken right away, it gives the healer time to at least back away.
You can also do kamikaze aoe by running into a pack of mobs and dropping an explosive trap. Not recommended unless you know what you're doing. You could kill yourself or transfer aggro of a billion bugs to a healer when you feign, which is NOT A GOOD THING.
The kamikaze trap technique works well in any instance with non elite packs of critters.