Current Best Gold Making Professions

[Jabberie]

The current meta is to take double gathering and once a month drop one of them and take up enchanting for an hour and then retake the dropped profession.

Legion changed how professions work. You have a ~30 quest chain to "learn" the profession.
With gathering, you get quests from gathering to get each of the 3 ranks per herb/mine node.
Skill level doesn't do much for you bar being able to loot a few mobs.
If you drop a profession, you can buy a book from it's trainer for about 1k which will give you back the quest rewards since you can't do them again.
You usually have to use 2 books to get everything back. Enchanting is the same in that a level 1 enchanter can DE all Legion gear.

So you do gathering for the month while collecting all your gear. Drop Herbing for example. DE all the crap. Pick up herbing for 2k again and go back at it.
4 to 6 chaos crystals will pay for your "repec" basically.

Herb/mine is the only profession I know that every rank comes from a quest so they're the best to drop. Alchemy is the worst.

Herb prices in particular are huge.

If making new toons, multibox gathering is "easier" with the same race for all. Taurens are naturally faster at herbing but you can get a glove enchant to do the same. Tank classes can't be dazed/dismounted but you can buy consumables to get that as well.

Edit
Since a boon was mentioned, Do Valsharah first. It's quick to get enough rep to get their shoulder enchant. Boon of the Harvester. It's bags give Fish and Herb.