Tailoring is a crafting profession that turns various forms of cloth into cloth gear. You can also create some tailoring only mounts. In BfA tailoring has several markets that are good from a gold making point of view. You can utilize the Tidespray linen bracers in the scrapper to get access to cheap expulsom. You can also craft the item level 300/310 tailoring armor. This armor does require expulsom, so it takes a bit more work than the blacksmithing gear. You can also craft bags, which typically is quite in demand as players always want more bag slots.
If you can Solo an instance, you have two options. The first is to take the place apart yourself and sell all the drops on the Auction House. For level 80 characters, Scarlet Monastery, Uldaman, and other mid-level instances are easily soloable, and are a very popular source of cloth and marketable blue and green items. If you're reasonably well-geared, and feeling more adventurous, Scholomance and Stratholme are also soloable, and can be extremely lucrative as a source of auctionable items.
At 98 you have the option to drop what you're doing and return to your capitol city to start the quest for your Legion Artifact weapon. However, I do not believe this is necessary to do right away unless you're struggling with kill speed in your current gear. I would recommend waiting for a natural pause, such as hearthing to repair and clear your bags. From 100 to 107 you won't even really fight mobs that often; only just enough to clear the way to any treasure you need to pick up.
The last farm on this list, actually I was surprised this farm eluded me for so long.  Generally speaking gnomergan is a huge confusing instance that takes some getting used to but if your a high value transmog farmer this does not scare you.  You can pull the entire instance and get access to a plethora of high value loot such a recipes, world drops, greens and even engineer supplies.  Overall this farm is shadowed by the Diremaul farm and Zulfarrak farm, but is an equal change of scenery with a wild card if you get the hot shot pilots gloves OR the mechbuilders overalls worth 400,000g and 60,000g respectively.  A pretty cool neat farm that noone really mentioned until now.
Although you usually don't want to buy items to sell from vendor, some items can be sold for much more than you pay for them from the vendor. There are a few reasons people will buy a vendor item for a higher cost at the AH. They vendor may be hard to get to, the recipe only sells in limited stock, or the buyer simply may not know where the item is from.

If you are not the leader of a high tier guild, do not worry because you can still make gold off of raids. This is the newly emerging GDKP runs that a respectable raider can put together (See why it is so important to keep a good reputation on your main toon?). Respectable raiders often take a few of their friends they can trust that have a lot of gear and bring random people along through the raid. Whenever a boss is killed, the items are auctioned for whatever base price you establish or more. You then split the money with your friends to keep everyone trying and happy, while you become richer without doing anything out of the ordinary. This seems like a perfect idea that can not fail, but it still has its risks. The tips below will help maximize the potential of the GDKP run.