Here is a tip that new players may not know.

The best gear for leveling is usually in instances. It usually trumps crafted stuff as well. (But crafted stuff can be good).

If you are a clothie, it makes sense to take up tailoring.

If you check out your character at wow armory, it even has sections to suggest upgrades.

Fastest way to farm those things is to get a higher up guildie to run you, or else pug.

If I'm pugging for a clothie piece, I'll try to construct the group so there are no clothies. Paladin/druid instead of priest etc.