The most important step in being able to buy a mount and make other large purchases should be self-evident: saving. Economize as often as you can, and don't buy anything unless you absolutely have to. You can burn through hundreds of gold even before level 20 by visiting the auction house for new equipment at every opportunity. If you do so, over the long haul you will be left with very little to show for it. Before level 20, keep your eyes on the prize: getting that mount. The mount helps you move faster. Faster movement means faster killing, faster questing, faster quest turn-ins, and faster leveling. It is the most important tool to fast leveling you can get at level 20, and infinitely more important than getting your hands on that Left-Handed Vorpal Cleaver of the Zipswitch that you could have purchased at level 23. Stay focused.
You will have to buy [Mark of Blackrock] or [Mark of Shadowmoon] at the Enchanter's Study with [Secrets of Draenor Enchanting]. These recipes cost 5 Secrets of Draenor Enchanting so you will have to wait 5 days until you can buy one of them. It's worth to wait because with other recipes you get 1 skill point / [Temporal Crystal], while with these you get 5 skill points / [Temporal Crystal].
This farm almost did not make this list. Even though I have had only a little luck with it, it seems to be gathering some popularity in the gold farming community.  Although I feel with the recent changes in 7.3,  this farm is very close to dying out.  Generally what you want to to do is pull every mob you can as you venture to the last boss in the instance.  The only saving grace of this farm (if you can call it that) is that some mobs are GUARANTEED to drop greens.  Guaranteed.  Whether or not they drop profitable greens is a different question, however it's a must-mention quirk you get from running this instance.  It also allows you to get your hands on some rare low level blues.
The idea of the expansion came up after the heroes of Azeroth dealt with so much external threats like the Burning Legion. In their own words, "so when we talk about what's the biggest threat in this world, is it the titan or is it the dwarf paladin that put a hammer in that titan's head"? As such, the enemy (at least during the early parts of the scenario) will be the opposite faction, a "vast army of world-destroying forces".[4]
Battle Standard of Coordination: This item gives you 15% bonus XP if you stay within 100 yards, with a 10-minute cooldown. Can be useful if you are grinding in an area or when completing a dungeon. If you plant the banner at the last boss of a random dungeon you will get 15% extra from the bonus XP as well as that XP is awarded when killing the last boss. You need to be friendly with your guild to get this. The easiest way to get it on a new alt, is to buy a Renowned Guild Tabard with you main and send it to your new alt. Now you need to join a guild with the “A Daily Routine” achievement completed. So open the guild finder, if you’re not already part of a guild, and look for a guild with a lot of members since they are more likely to have the achievement, and ask to join. Then buy the Battle Standard of Coordination.

The most rare and expensive poly morph tome drop and for a reason.  The bears that drop it are VASTLY spread out across the zone and getting one can mean hard farminh for a while.  They also take a while to respawn so watch out.  Getting one to drop can mean a staggering 48,000g, and on top of that compared to other pet farms and such, they have a much higher drop chance.  Simply head over to dragonbligh ona mage character (class trial is perfect) and start the killing.  Cross you fingers as there is an 0.4% chance to get one on each kill.  Thats actually pretty high considering..

Enchants. I honestly wasn't 100% certain which enchants were best, since scaling has screwed up a lot of things. IMO, just pick the enchant for each armor slot that has the highest bonus without level restrictions. The exception is that you'll definitely want Mark of the Hidden Satyr for your neck piece, and probably Elemental Force for your weapon. Both of these proc consistently and strongly across all levels.
Profit is only created if you make sure your costs are less than your earnings. This is not so much an issue for gatherers who simply trade in some time and effort to gain their wares, but for production professions, this must be kept in mind. Many high-end items that sell well require materials that cannot be provided by the gathering profession normally paired with your production profession. To craft these items, purchasing the raw material from the AH or another player becomes necessary. You must keep record of how much you spent to obtain these materials, or else you may price the finished product inaccurately, either too low that you sell it at a loss, or too high that you can't sell it all.
This farm very much resembles the Dire Maul farm in that it allows you to hit multiple markets without having to do too much.  You can mageweave, runecloth, greens, world drops, and herbs all from this one single spot with the addition of countless transmog items.  I personally love this spot – however I feel I stumbled upon it a little to late.  The benefits is that this is the LARGEST instance in the entire game – literally.  You can spend up to 15 minutes pulling the entire instance.  You are rewarded however with an abundance of drops of all kinds. You can quickly fill up your inventory here.  If you need greens form the 47-51 area, this is your spot.  As mentioned, you will also get soo many trade goods that it's hard not to fill even the biggest of bags.

Updated - New Hunter Pet Family Tome, New Year Blizz Video Update: A way has been found to obtain the tome, but Blizzard have already clarified that it's unintended, and it's also making Hunters look pretty bad in PUGS as well! You can actually hearthstone out of the Zul encounter on heroic and if he dies later, you get the tome. However, muffinus had this to say about it: World of Warcraft WoW Dec 22, 2018 at 20:37 by Starym 3 comments
I do not recommend going for TBC, although I remember Hellfire peninsula to be decent, everything else is rather slow. Instead go for WotLK, Borean Thundra gets you levelled very fast, and then you can head straight for Icecrown at 67, which is also insanely fast, although admittedly has a few elite quests. You can go to Sholazar Basin alternatively. 2 zones should get you 60-80 no problem.
The best way to collect AP is through world quests, a system that allows players to complete menial tasks to earn moderate rewards. A finite amount of AP spawns on the map through these quests — generally at least 2,000 a day. I’ve likely done most of these quests close to 20 times in the course of preparing my various characters in the 45 days since the expansion launched. In some cases, I’ve replayed them as many as 50 times.
Incorporating an accelerated leveling pace is *definitely* something we want to incorporate in to the new addon My hope is to allow an option for you to set yourself to one or two higher speeds, where the guide will skip some steps along the way. The steps will have a special tag that lets the addon know to skip them if the person has that setting enabled.
Footholds into enemy territories can be done as you grow in levels and should be completed before reaching Level 120. Take the time after completing your first zone to do your first foothold, or you can choose to complete one as soon as you gather your 100 War Resources which will prompt you to return to your mission table area where the first foothold quest can be obtained. Similar to how your initial zone selection was largely irrelevant, this selection is, as well. Simply pick one and complete it to earn your Mission Table second champion. Send your champions out on missions, recruit troops, and then head back out to quest in your second zone selection.
Another potion of treasure finding farm that was made extremely popular by the YouTuber Oldbess.  In this spot, you are simply to patrol the entire southen river basin in Twilight Highlands, just around the Verrall Delta area.  The goal of this farm is to kill water elementals for their volatile water, which trends around 50g per drop.  Combine this with the cloth and the treasure chests, and you have a cool  nifty farming spot – thats rarely populated these days.

Now that we have a lot to post we reached a point where we have to plan what items we post on an 12-24-48 hour cycle. The auction house fees for Warlords of Draenor items are extremely high. And the values of the items are really screwed up. A lot of the weapons or armor has an item value of 5-10.000 Gold. But they look plain bad and the chances of selling them is pretty low.