playing the auction house. cooking materials are fantastic right now if you can corner a couple. 3k is plenty to start on those. the BEST way was to camp peacepipes and murder the AH with rare rep items, but blizzard fixed that and made a bunch of people rich. since the market is so volatile right now, i've been changing up items frequently so as to not get hosed on anything. try lots of items, it all depends on your server.
tillers/cooking/farming on your farm is the best way though. the ironpaw tokens buy sacks of 25 veggies or foods that you can sell for as much as 35-100g per on some servers. or, spam general and offer up your ironpaw token redemptions to gold to people looking to powerlevel their skills or reputations with the Friends. some guys were getting 500g a token there for a couple days, making a killing. i don't think you need to be 90 to do that stuff! buying and reselling has no level requirement