Apologies if this is an already widely known tactic.
If you play as DPS, then you know how terribly long the queue is for the Random Dungeon team making system. Sometimes it takes literally forever and a day to get a team going.
Want to know a faster way to get into a team and off earning your Emblems of Frost/Triumph without waiting until the cows come home?
Grab a friend who plays a class that 'can' tank. For the people who are completely ignorant about class abilities, that's Warrior, Paladin, Deathknight and Druid. Even if they only heal or DPS, have them queue as role = Tank. Once the team gets put together, which should be absurdly quick, have your buddy enter the instance and then drop team. Immediately elect to search for a replacement. This will put you at the front of the queue instead of at the ass end of it, giving you the first Tank available.
Voila! Instant reduction in frustration!
And knowing is half the battle.