Hello all, this is my first post =)
For me, The best trick as a Mage, especially with good gear (item lvl 251+), is H nexus on the Grand Magus Telestra fight. If you play your cards right, you can spell steal a 1 minute haste buff from the Mage Hunter Ascendant right before the fight. All you have to do is pop cool downs and spam Arcane blast and you pull 20k dps and the boss dies in 6 seconds with a good group, especially now a few days before Cata comes out.
What other Mage tricks have you guys found throughout WOW? (i.e. blink drop and so forth)