I've been gold farming for almost 1.5 years now and have made lots of money so I've decided to write my own guide.
Tips
You will eventually be banned by gold farming. There is no way around it. The key is to profit as much as you can before getting banned. Don't complain when you get banned.
Mule the gold every few hours so you do not risk losing out on profits
Find a good private script
Buy a VPS to increase the size of your farm
Do not bot stupid stuff