This spot actually kicks BOOTAY.  And I only say that because it's so hidden, unique and quirky that I had to add it to this list, despite it being a method rather than a farm.  Generally what you want to do is some sneaky arbitrage.  We'll be buying the items Royal olive, Dalapeno Pepper, River onion, and Muskenbutter from the vendor for 2g – and reselling them to the AH for 4g+. This is an awesome way to take advantage of players laziness and the demanding reagent requirements for some of the higher end recipes.  By selling from the vendor to AH, you can make easy gold – in fact I suspect most cooks do not know these reagents can be purchased from NPC's.
At Level 38, you unlock an additional pet ability. The ability you unlock depends on the spec of your pet. Ferocity pets gain Primal Rage, which is a Bloodlust/ Heroism effect that increases the Haste of you and all party members by 30% for 40 seconds. Tenacity pets gain Survival of the Fittest which reduces you and your pet's damage taken by 20% for 6 seconds on a 3-minute cooldown. Cunning pets gain Master's Call which removes all movement-impairing effects from your pet and a friendly target, and makes them immune to movement-impairing effects for 4 seconds. The friendly target can be you. It has a 45-second cooldown.
You should equip new quest rewards when their item level starts beating out your previous set of gear. 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 are worth using over Tier gear in most circumstances.
There is an alternative really cheap method, but only Blood Elves can benefit from it. Due to their Racial Ability it allows them to gain ten free skill ups by converting a Large Prismatic Shard into three Small Prismatic Shards and back again. Only the conversion from one Large Prismatic Shard to three Small Prismatic Shards is effected by this. Therefore, you will only have the chance to gain skill ups half of the time (since the other half of the time you'll be converting back to three Small Prismatic Shards). This can make for a fairly lengthy session in gaining your ten free levels.
Whatever your approach, if you use some common sense and apply yourself, you can make significant quantities of money in the game. By managing your cashflow, conserving and budgeting where you can, and investing wisely in those activities that make you money, you can become financially solvent relatively early in your career, and remain comfortably well-off (while still buying good gear) at level 80. Good luck!

Allied races: Our new allies will join the factions and players will be able to unlock the ability to play their race. There are 6 planned for launch. Horde: Nightborne, Highmountain tauren, Zandalari troll. Alliance: Void elf, Lightforged draenei, Dark Iron dwarf. Additional races are planned for the future. Receive a Heritage Armor set, if you level an allied race character to level 110.[5][6]
Make sure you have the two Flight-Path toys purchased, as this can save you time. It won't have EVERY flight path, but will have major locations for faster travel if you need to switch zones entirely(which you will). If you buy the toys on one faction, it unlocks for the other faction as well. So don't spend double the gold! These toys can be found at the heirloom vendor(Undercity for Horde, Ironforge for Alliance)
Special note: At 110 it's almost certainly worthwhile to go and immediately get your Heart of Azeroth and first piece of Azerite gear from the BfA opening quest. It doesn't take long and provides pretty high power levels. I'd then return to Legion quests until 111 or even 112, since the power of these items will increase your kill speed significantly over the scaled enemies of BfA content.
Picking up herbalism and mining is the best professions to have while leveling. Not only will you earn gold as you level, but you will also get extra XP. At level 20 you will get over 500 XP for picking up a ore or a herb while killing a mob only gives a little over 100 XP. Don’t go out of your way to pick herbs if you are trying to level quickly, but pick the ones that are on your way. Leveling from 110 to 120 can be done pretty quickly just by doing this. There are a few items that will help you if you decide to use professions while leveling:

You’ll gradually gain access to new War Campaign quests while leveling up to 120, requiring you to establish footholds on Zandalar, send followers on missions at the mission table, complete Island Expeditions, and reach Friendly reputation with Order of Embers, Proudmoore Admiralty, and Storm’s Wake. After you’ve reached player level 120, new quests will unlock at specific reputation levels with 7th Legion.
Most of the players make the mistake of only listing 30-50 transmog items on the auction house and then hoping to get half of them sold until the next day. Me and a lot of other gold farmers and transmog sellers do have 3.000-10.000 items on the auction house across various realms. It does not mean you have to do it that way – but if you have 1000 items listed, chances are higher you can sell up to 10 per day. With only 100 items listed, you have to be lucky to sell one. Of course, the sells are not guaranteed if you post more items. But i’m sure you have a lot more fun if you open your mailbox and 10-20 items are sold