You should equip new quest rewards when their item level starts beating out your previous set of gear. For healing, if you are currently wearing Tier 21 gear, it is best to let the quest rewards significantly beat your existing item level before using them. With that said, you will unlock Azerite pieces early on, which can be worth using over Tier gear.
If you can answer all of those questions with yes, then you are in a position to make a lot of gold! You can continue doing every step to get to the gold cap as quickly as possible. The security achieved through this can buy you virtually anything you desire in the game, including achievements that would otherwise be impossible on your own, which leads us to the final gold making tip - Selling achievements. If you are the leader or officer in a guild, you can take good acquaintances on your raids with you for achievements like finishing ICC or any other hard raid achievements that your guild finds easy and manageable. I have seen achievements go for 20k+ if you find the right client! This is very situational, however, and is by no means necessary to hit the gold cap, it just helps!
Sometimes you can make money by crafting items with ingredients supplied by other players who give you a tip to make the item. This is not necessarily a reliable source at low levels, but it can be a good supplemental income source at higher levels, particularly if you have good recipes. And if you can charge for the customer using your materials (as opposed to materials supplied by him/her), you can mark those up.
Get your item level as high as possible. Having the best gear is always going to help you when clearing content, so upgrading your individual pieces of armor will be important in the first few days after the expansion’s release. If you’re looking to get ready for Uldir, then you’ll want to be around item level 350 by the time that raid is released on Sept. 4.
Allied races are variants of existing races. The Void Elves are a version of Night Elves, while the Highmount Tauren are, you guessed it, a version of the Tauren. Four allied races are already in the game before launch and two more, the Dark Iron Dwarves and Mag’har Orcs, were added after Battle for Azeroth launched. Each Allied Race has its own racial abilities. You can also unlock a heritage armor set by leveling any Allied Race to the level cap.
Inscription is a very strong gold making profession. It utilises herbs and turn them into pigments for inks. The main outputs are glyphs that give cosmetic effects for your character. You can also craft trinkets that are upgradable with obliterum and Tome of The Tranquil Mind. As with Jewelcrafting you can make gold just by milling herbs. The glyphs are generally profitable, even though competition is usually high. The Darkmoon Deck trinkets have been amazing and so can Tome of the Tranquil Mind be.
This is a risky way to make money, and not recommended. Tell a player that if he beats you in a duel you will give him 10 gold, but if you beat him he has to give you 5 gold. This can be very effective if you are skilled in PvP and make the bet with a trustworthy person, or friends. It is a very risky strategy, as you may lose gold, or the other player won't cough up the money anyway. You will also get a bad reputation if you don't cough up the money in the case of defeat.
EDIT: Apparently this transmute *does* share a cooldown with other transmutes outside of the TBC transmutes. So again I would check prices on your server and make sure it's worthwhile to have and use this transmute instead of certain other ones. I believe it shares a cooldown with all other daily transmutes, even those that aren't listed in the profession text as a daily cooldown in game. Kinda unfortunate, but again I'd say compare prices and check the stock of Primal Air on your server because it could still be a great transmute to have if the stock is low on your server.