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.
Warfronts are larger, 20-man instances that take inspiration from the Warcraft strategy games. Players are deployed on the Warfront to collect resources, destroy enemy troops, construct buildings, and eventually launch an assault to take over the enemy base. These battles take 20 to 40 minutes to complete and, unlike Island Expeditions, don’t offer a PvP mode.
Guild Banners. The Banner of Cooperation and Battle Standard of Coordination will increase the experience from kills. They both have a 10 minute cooldown, but when you use one, the other is only locked out for 2 minutes. I was very bad about using these, so it might be worth using a macro to drop them on your first attack against an enemy. Keep in mind you must have reputation with your guild before being able to buy these, so new character may have a bit of a wait before picking them up.
Heirlooms. At the bare minimum you make sure all the armor pieces upgraded to 110, since this is the lion's share of your experience increase. Neck and Ring upgrades are secondary, but still important due to being able to enchant them. Trinkets can't be enchanted, but you'll want them at max as well, if only to save time by not having to worry about replacing them as you level.
You should try and quest efficiently - pulling several mobs if you can handle it, using your burst cooldowns while questing to kill everything faster. Many people would think that a 10-minute cooldown like Bloodlust is useless in open world, but you can do a "kill-15-mobs" quest in like 30 seconds if you pull a lot and use it. A free quest every 10 minutes is not that bad.
The most simple thing is TradeSkillMaster. This AddOn shows you quite an amount of information in the items tooltip. In my opinion, DBRegionMarketAvg the best source. It tells me the price, an item was posted on all EU realms in the last 14 days. Why not DBMarket? DBMarket only shows you the items value from your server in the last 14 days. This value often gets manipulated. Some people start to post an item with a 500g value for 500.000 Gold on the auction house for several weaks. As a consequence, DBMarket is rising towards 500.000 Gold. If you use DBMarket with 100% and post your item for 500.000 Gold, nobody will buy it.