Fastest Gold-Farming Method For Professions, Significant Gold Arbitrage Profits From Cross-Realm Trick (Patreon)

Since cross-realming add-ons were heavily restricted gold farming techniques have become significantly less profitable. 

There is a workaround, or at very least a partial workaround (in some cases this method is actually better than using cross-realm assist was pre-nerf). 

Set up a class trial character. It is generally a good idea to do this on a low population realm. Take the class trial character to a farming location such as a number of nodes in close proximity, perhaps after having learned professions in new Dalaran. Form a group using group finder. 

A main can be taken to the same location. Provided the group leader is in that location other characters in the group will switch realms. 

The two players have to be logged-in for realm transfer to take place. This can be done by using "Method Zero"-open two wow clients, enter the game on the group leaders, then log-in on the secondary client without logging out the group leader. The group leader will still be in-game and actually visible for about 40 seconds after you log-in on the secondary character. 

You can do most of the things you used to be able to with cross-realm assist using this technique and it is the fastest possible farming technique for any conceivable profession, since generally speaking it is faster to log into a fresh series of high density nodes than it is to chase ever more scarce nodes on a farming route and/or wait for nodes to respawn. 

The major advantage of this over cross-realming is that you face no competition since every serious gold farmer was doing it but no one knows about this (yet). Additionally you can focus your cross-realming on low-population realms rather than just random ones which is very useful for farming rares.

There is no effective limit to the number of toons you can do this with, though there is a limit of 8 class trial characters.