YouTuber Oldbess recently uploaded a video about this cool method.  Generally completing the scenario "Deaths of Chromie" will allow you to pick up the item "Time-Lost Wallet" in excess.  You can get it from just killing the mobs or actually completing the scenario in full.  By then end you will have dozens of time lost wallets.  Each wallet awards 50g AND a rare chance at getting the ]bronze proto-whelp[/U] pet.  In the video, this spot was VERY hard for to pull off as it requires a high item level.  With an 809 item level I struggled all throughout the scenario and could not make this spot profitable for the time invested.  The good news is, if you can get it done, the gold you make will be entirely liquidated – the rewards are 50g raw for each wallet turn in.  I suggest you watch it on Oldbess's channel for full details.

Beyond that the constant amounts of RNG on top of RNG has made the game not only frustrating but unfun and unrewarding. It is clear with the current game design decisions the goal of bfa was not to create an exciting experience and to refresh world pvp and faction pride, but to test the player base and see how long subscriptions could be pushed with the least amount of content. Class specific raid gear, tier sets, removal of any sort permanent player progression and a complete draining of class skills has left BFA with less and forced players to grind more only with the knowledge that like Legion all your work at the end of the day will be worth nothing due to end game catch up mechanics and removal of the azerite necklace at the end of the expansion.

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.
When assigning a selling price, do not aim for too low a price that would give you too little profit, but certainly do not assign too high a price. Too much greed is never a good thing, and the AH is filled with items that do not sell due to excessive inflation. A very common tactic in the AH is to sell for lower than what another player is offering, and many players make a lot of money that way. Similarly, losing sales thanks to being undercut is never fun. Aim for as low a price you can that will still make you a good profit. If you can keep producing the same item over and over, sell cheaply yet make a good amount of the item, you will reliably make a lot of money by volume. Moving inventory is the best kind of inventory.
Making gold is all about finding the balance that works best on your server between all the above methods. When you find that balance, repeat, repeat, repeat, until you get the results you want. Never make any rash decisions without first consulting the economy. If you do not think you can make a for sure profit, then do not do it! Change only when necessary, because your clients become accustomed to certain practices that keep them buying from you even if under cutters offer a slightly lower price. If the customer is always right, then show that to them and you will be much more profitable!
I'm very, very interested in a guide that takes into the following: 1) Dungeon finder; and 2) Heirloom items. I've never helped with a guide before, but would be open to help in collaborating on the project. With the leveling guides I've used (primarily this one) I, too, find that I level at a rate that throws the pace of the guide way off (not its fault at all, I can't say enough good stuff about the guide) to the point that I get frustrated and just queue up for dungeons.

Vigilance Perch is essentially an automatic mount when out of combat. Despite its tooltip, it only allows you to fly in flying zones, so you will not be able to fly in Battle for Azeroth zones. This is a great Legendary to pair up with Sephuz's Secret. Choosing between this and Apex will come down to personal preference and how you prefer to level. When speed-leveling with consumables, you will not get full value out of the mount ability of this Legendary. If you are just leveling normally, try them both out and see what works best for you.
Alchemy is a great profession for gold-making as the main outputs are consumed on use, this means that there will always be demand for new potions and flasks. The old world recipes are also very profitable. Sadly I don’t have Legion alchemy so I can’t personally help you. The best guide I was able to find on the internet is this video guide by Ninja Kuma.
Blacksmithing is a crafting profession that uses bars obtained from melting ore to craft plate armor and weapons, as well as some assorted cosmetic items. In Legion you craft ilvl 850 gear (demonsteel), a mount and a legendary. These are the main gold making opportunities with blacksmithing. Blacksmithing can also create a lot of transmog gear from old expansion. Some rare recipes have looks that are very sought after primarily for weapons.

From “The Burning Crusade” expansion, weapons like Klinge der Zauberei, Die Nachtklinge and recipes for different weapons are really valuable. The best example is Pläne: Teufelsstahlangschwert, worth 500.000+ Gold. These items are World Drops, you can find them in all raids and dungeons. I don’t know any Open World Drops, but that does not mean there are none. Another great transmog source are world bosses and rare spawns on Outland.