This is especially good for Horde since most of this faction is going for the Scryer reputation. You can sell Scryer reputation items (Arcane Tome, Sunfury Signet and more) on Alliance side, but the market is much less attractive.
A good and easy place to farm, is Path of Conquest. It is in Shadowmoon Valley, and the area is filled with level 70 blood elves.
Depending on your level, it will take from 4 to 15 minutes to kill them all. They have a pretty fast respawn time so you can start forever.
In about 10 minutes, I got almost 30 gold, over 150 Netherweave Cloth (still selling strong on most realms), some greens (5 or 6, which became Arcane Dust and Greater Planar essences, this sells fine too), 60 Sunfury Signets (used for reputation) and four arcane tomes (reputation and enchants).
To be honest, the reputation items take time to sell, only few people are interested. The netherweave sells easy or if you have a tailor, it can be turned into Netherweave Bags, which still go from 15 to 25 gold each, depending on the realm.
So what are you still doing here reading tips! Go Outland and farm! 🙂 (Scorpyo)