Spend an hour or more on dailies or farming wow gold

The idea behind playing the AH is to buy low and sell high. Instead of spending an hour or more on dailies or farming wow gold, you can spend an hour or so combing through the AH for things that are on there way cheap that you can buy and then sell higher. Miners gather metal ores and occasionally rare gems. Mining is infamous for being the most reliably lucrative gathering profession dating back to Vanilla Wow. Ores can be smelted into metal bars used to craft Blacksmithing and Engineering items, and ores can also be prospected by Jewelcrafters to produce rare gems. Due to the sheer number of uses for the products that Mining yields it is always in demand.

Another thing to keep in mind is that you're going to want a lot of bag space for those marathon gathering sessions. Engineering and Blacksmithing both need massive quantities of the stuff, and it sells fast, and for a fairly high price. One word: Tanaris. You could travel around the whole thing, but I've found it much easier to start at Gadgetzan, and cut across the desert to the start of the bug area, checking all of the little rock outcroppings on the way.

The difference between making good wow gold gathering and making great wow gold gathering is efficiency. You need to know where resource nodes spawn and have a 'path' that you use to navigate a zone. You're going to obviously need Northrend Epic Flying to move around quickly -- a 280% speed mount is great, a 310% mount is even better. In two hours of solid herb gathering in Scholazar Basin it's not unusual to use 60 or more bag slots so be prepared!