Over the past couple of months, I've discovered a means of making some money in-game that I hadn't known of previously.
This method is offering to run lower level characters through instances for a fee. Just earlier today, I was clearing some Alliance out of the Crossroads when someone messaged me and offered 2g 50 for a fast run through the Wailing Caverns.
WC runs may not be all that profitable, but some of the others can be. The trash alone from a Scarlet Monastery Cathedral run is usually worth around 5 gold in my experience. Add in another 2 gold as my fee, as well as being able to do that maybe once every 20 minutes if I'm fast, and if I'm able to get a single blue to disenchant, at least a theoretical number of 30ish gold an hour becomes possible; probably even more if I'm running the Armory, as it's faster. Not much, perhaps...but a steady trickle, and I'm thinking it could at least help towards my epic mount if I work on it. I know everyone says that the way that an epic mount should be paid for is purely via Outland quests, but I've been finding that all of that money has either been going to the AuctionHouse or ammunition costs...it's one of the downsides of Survival being such a gear dependent spec, as well as the fact that I'm not really raiding yet.
Instance farming is definitely something that some of you might want to look into, though. As well as being profitable, the SM Cathedral and BRD are fantastic instances for Hunter training and practice in particular; BRK has written about the Cathedral in that respect, and the early trash in BRD is very good for learning about three mob pulls with Wyvern Sting. I also still haven't soloed ST yet, either...got to get to that!