I dont understand your response to the Felblight Leather. It's crazy lucrative.
Otherwise all the major gold making tactics have been worked out of the game since they want people to grind. The best way is to find a corner that hasn't been exploited. My best was in Cataclysm, selling Eels on AH for hundreds of gold. For some reason fish was super expensive that expansion. Made 200k gold before people started muscling in on my scheme and forcing prices down.
Now enchants have bombed, gems are gone, crafted items are worth sod all this late in the expansion as you can only have 3 (which is retarded) and they're all outweighted by easily found items for casuals.
Felblight, run old raids (2-3k per run) or buy it. Sadly.