If you a 55 already somewhere, you can start a DK on the server you are going to level your guys on. give him mining/herbing + skinning. This can be quick gold for your guys. With RAF you outlevel areas way to fast and you don't want to slow your guys down with trying to find mines or herbs. that's when the DK comes in handy cuz he already has his fast mount and you just have to spend maybe 30 minutes a night gathering and what not to put on the AH.

You can also plan ahead and just do the HFP quests with your DK and sell all the rewards for an easy 300g. This shouldnt take you more than a couple hours. Again this is all advice considered if you already have at least 1 high level somewhere.