For items that you can gather directly, you have the choice of either going out to gather them yourself or to buy them from the AH. The former adds no cost to your item but requires time and effort, while the latter can be quick and hassle-free. Even should you choose to get the materials yourself, don't forget to add them to your cost — your labor and time should be compensated for, even if just a little.
-Global Cooldown- Almost all spells are now on the global cooldown. This has slowed gameplay down quite a bit and you won't get to use the full potential of your spells cooldowns. For example, you cast a spell that increases your damage for 15 seconds, after the global cooldown and you're able to cast again, you now only have 13.5 seconds to make use of the remaining time. There are far too many spells on the global cooldown that shouldn't be.
Stormheim is the zone you want to start it. For some reason Legion treasures are not worth any experience like they are in WoD...except in Stormheim. I haven't been able to find out any reason for this, and it's possible it may get fixed/nerfed at a later date. But for the time being you REALLY want to jump from treasure to treasure to augment your quest experience.
As late as possible. Early on, you’ll want to follow the missions in Battle for Azeroth right up until you get the option to send a follower on a two-hour long quest. As soon as you get there, stop doing the War Campaign missions. You can come back to them once you have reached something like 119 and a half and finish leveling with those if you want. If you don’t use these missions to cap off your leveling journey, then they’re the first thing you’ll want to do once you reach max level.
REALMS Aerie Peak Aman'Thul Area 52 Arthas Baelgun Barthilas Blackrock Bleeding Hollow Burning Legion Cenarius Dalaran Darkspear Earthen Ring Emerald Dream Frostmourne Garona Garrosh Hyjal Illidan Kel'Thuzad Kil'jaeden Korgath Lightbringer Mal'Ganis Moon Guard Proudmoore Ravenholdt Sargeras Saurfang Shattered Hand Stormrage Stormreaver Thrall Tichondrius Turalyon Wyrmrest Accord Zul'jin Aegwynn, Bonechewer, Daggerspine, Gurubashi, and Hakkar Agamaggan, Archimonde, Jaedenar, and The Underbog Aggramar and Fizzcrank Akama, Dragonmaw, and Mug'thol Alleria and Khadgar Alexstrasza and Terokkar Altar of Storms, Anetheron, Magtheridon, and Ysondre Alterac Mountains, Balnazzar, Gorgonnash, The Forgotten Coast, and Warsong Andorhal, Scilla, Ursin, and Zuluhed Antonidas and Uldum Anub’arak, Chromaggus, Crushridge, Garithos, Nathrezim, and Smolderthorn Anvilmar and Undermine Arathor and Drenden Argent Dawn and The Scryers Arygos and Llane Auchindoun, Cho'gall, and Laughing Skull Azgalor, Azshara, Destromath, and Thunderlord Azjol-Nerub and Khaz Modan Azuremyst and Staghelm Baelgun and Doomhammer Black Dragonflight, Gul'dan, and Skullcrusher Blackhand and Galakrond Blackwater Raiders and Shadow Council Blackwing Lair, Dethecus, Detheroc, Haomarush, Lethon, and Shadowmoon Bladefist and Kul Tiras Blade's Edge and Thunderhorn Blood Furnace, Mannoroth, and Nazjatar Bloodhoof and Duskwood Bloodscalp, Boulderfist, Dunemaul, Maiev, and Stonemaul Borean Tundra and Shadowsong Bronzebeard and Shandris Burning Blade, Lightning's Blade, and Onyxia Caelestrasz and Nagrand Cairne and Perenolde Cenarion Circle and Sisters of Elune Coilfang, Dark Iron, Dalvengyr, and Demon Soul Dawnbringer and Madoran Darrowmere and Windrunner Dath'Remar and Khaz'goroth Deathwing, Executus, Kalecgos, and Shattered Halls Dentarg and Whisperwind Detheroc and Shadowmoon Draenor and Echo Isles Dragonblight and Fenris Draka and Suramar Drak’Tharon, Firetree, Malorne, Rivendare, Spirestone, and Stormscale Drak'thul and Skywall Dreadmaul and Thaurissan Durotan and Ysera Eitrigg and Shu'halo Eldre’Thalas and Korialstrasz Elune and Gilneas Eonar and Velen Eredar, Gorefiend, Spinebreaker, and Wildhammer Exodar and Medivh Farstriders, Silver Hand, and Thorium Brotherhood Feathermoon and Scarlet Crusade Frostmane, Ner'zhul, and Tortheldrin Frostwolf and Vashj Ghostlands and Kael'thas Gnomeregan and Moonrunner Greymane and Tanaris Grizzly Hills and Lothar Gundrak and Jubei'Thos Hellscream and Zangarmarsh Hydraxis and Terenas Icecrown and Malygos Kargath and Norgannon Kilrogg and Winterhoof Kirin Tor, Sentinels, and Steamwheedle Cartel Lightninghoof, Maelstrom, and The Venture Co Malfurion and Trollbane Misha and Rexxar Mok'Nathal and Silvermoon Muradin and Nordrassil Nazgrel, Nesingwary, and Vek'nilash Quel'dorei and Sen'jin Ravencrest and Uldaman Ravenholdt and Twisting Nether Runetotem and Uther
Now, on the other part of the equation, the items that return materials on mission finished are overlooked. Looking at this Wowhead comment https://www.wowhead.com/item=162114/crimson-ink-well#comments:id=2607578 the most lucrative ones are the disenchanting rod (returns enchanting mats, best case scenario, 10x veiled crystals) and the magnetic mining pick (returns ores, up to 40x Stormsilver). This is totally server dependant, but you will need to check which ones are worth where you play.
The majority of you (myself included) don't find farming fun. You don't have 20+ hours to burn each week on an activity that you find dull and mindless. Because of these things alone, you may try but you'll never be able to commit to doing this week in, week out, and this is why you'll fail. Repost after repost, without seeing success, you'll simply call it, and be just another guy who saw a transmog youtuber, tried to get into the transmog business, and quit after a day/week/month.
For those interested in more details on spending wisely, and generating good cashflow, we cover a number of topics in more detail. Please note that this guide represents the accumulated wisdom of many people. You don't necessarily have to do all of these things--there is no one "right" way to make and manage money. However, these pointers will give you ideas on how to establish a firm financial foundation for your character.
These are Warlock- and Mage-only skills which can net you some money. It's not much, but a few gold is worth it. Note that Mages have an easier time with this than Warlocks as Warlocks need to be at the location for the summoning and need an additional person (a 3rd) for the group to help out with the summons. Mages only need the reagent to open the portal. While the Warlock doesn't incur a cost (except the loss of a soul shard), the Mage will typically be more successful at finding employment using this method.
As always, I will monitor and update this guide as new information comes in. If I've gotten anything glaringly and completely wrong, just tell me with as much data as possible. The idea is to find the fastest possible leveling method, NOT to argue about how good or bad individuals are. If you have hard data, post it! If you have an idea, let the thread know so we can test it!