So... peeps have been trying really hard to twink their chars. Here's some advice before its too late :P.
Here you go:
1. Level up your engineering to 425 if possible for levels 1-71. Levels 72 onwards should level Engineering to MAX. This would require about 4000 gold unless you have another proffession which can provide mats for the stuff to be made in Eng.
2. Buy off better gear off the Auction House. This would require some gold too :P.
3. Freeze your exp when you are running dungeons to get blue gear from the satchets you get at the end of every RANDOM dungeon/ gear drops from mobs and bosses. This would cost 10 gold to freeze your exp and it would cost the same amount to unfreeze it again (when you decide to start gaining experience again).
4. Enchant your gear/ weapons. Click the 'disenchant' option whenever you can roll for an gear if possible and you would have enough mats for Enchanters to enchant your stuff.