Mining is one of the three gathering professions in the game. You mine from ore deposits for all the various ores in the game. Your customers will be blacksmiths, engineers and jewelcrafters. You can make good gold per hour from tons of different routes both farming for legion ores and farming old world ores. I personally don’t farm, so I can’t tell you the best routes, but check out Oldbess guide on mining for some great spots.
Allied races aren’t much better. You can only earn them by grinding out reputation. It doesn’t take that long but casual players will need to invest a couple weeks primarily to it, and focusing on that grind will take you away from others, like earning gear. Each race has its own grind, but the things you do to work through it remain the same, adding to your boredom.
Skinning is both highly profitable and convenient, in that you will be skinning the monsters that you're already killing as you level. A skinner starts by collecting relatively worthless ruined leather scraps, but soon moves on to light leather, which can be sold for a good profit. An excellent way to farm leather is to skin the kills of other players, especially if you are following along in the wake of a group. However, do wait to start skinning until it's clear that the other player has abandoned the kill. Don't assume that the other player doesn't skin just because they are not a leather-wearer, for example. Note that your chances of getting a better grade of leather increases with your experience; it is possible, though rare, to get light leather from rabbits. Higher grades of leather yield higher profits. A skinner/miner has potent earning power through the auction house, but often runs out of inventory space.
EXPLORE TWO FABLED KINGDOMS – As a champion of the Horde, travel to Zandalar to persuade the trolls to lend their naval might to the war effort. As a defender of the Alliance, sail to the seafaring kingdom of Kul Tiras, home of Jaina Proudmoore, and rally its inhabitants to fight for your cause. Once you’ve successfully recruited one of these proud kingdoms to your faction, infiltrate the enemy’s newly claimed territory.
Sometimes you can make money by crafting items with ingredients supplied by other players who give you a tip to make the item. This is not necessarily a reliable source at low levels, but it can be a good supplemental income source at higher levels, particularly if you have good recipes. And if you can charge for the customer using your materials (as opposed to materials supplied by him/her), you can mark those up.
AH Profits Alchemy AoE Farming Auction House Flipping Auction House Tips Badlands Battle Pets Blackrock Ore Blacksmithing Borean Leather Dark Whelpling Embersilk Cloth Enchanting Engineering Felblight Fishing Garrison Hellfire Peninsula Herbalism Hillsbrad Foothills Icecrown Instance Farming Kun-Lai Summit Leatherworking Linen Cloth Low Level Farming Mining Mote of Harmony Nagrand Northrend Primal Spirit Rare Boss Farming Rugged Leather Silithus Silk Cloth Skinning Sumptuous Fur Tailoring Tanaan Jungle Transmogrification Gear Twilight Highlands Uldum Volatile Air Warlords of Draenor Windwool Cloth
Buffs. Food/Flasks/Scrolls/Potions/Elixirs are a small, but noticeable, buff to your killing speed and survivability. If you have a max level character that can already supply you with cooking or alchemy, you'll be very well off, because the AH is a cesspool for this. I can't really give you specific foods or potions to look for, since each AH is going to have different supplies. Generally speaking, lower level foods are going to only last 15-20 minutes until you can buy the more powerful versions at 60+. Look for anything that adds versatility or your primary stat, and buy stacks for each level range(1-60/70/80/90/100).
If there would be a transmog server #1, all transmog vendors would transfer there and the market would get destroyed fairly quick. In general, Roleplay-Servers like Argent Dawn or The Aldor are better server for selling transmog. On high pop servers you have a lot of other players selling stuff and as a result, low prices. On low pop servers prices are acceptable, but you have no buyers. So there is not recommendation for a server really. Its up to you.