The great thing about a new expansion is the flux of people constantly looking for new gear. Fresh endgame toons will seek out crafted epics (as will PvP folk until they’ve earned enough points to get some Honor goodies) because they don’t need to farm them to drop. This, of course, creates a demand that likely can’t be met yet in terms of supply.
Many people are leveling to 85 and some are already raiding. There are not a tonne of people who have maxed out their respective non-gathering professions yet. So, the ones who have are in position to make a killing early on. If you’re among those who hasn’t gotten their skill points to 525 or perhaps aren’t even 85 yet either, there’s still hope. Commissions.
Get the materials yourself for recipes. Whether it’s through farming, or simply buying them off the Auction House, determine the cost of the end product against the cost of the materials. In many cases, there’s a solid profit margin and one that allows you to go above and beyond in terms of tipping your commissioned crafter. If you tip well, your requests probably won’t be questioned much if you want multiples of something. When in doubt, mention it’s for guildmates. Then flip the items to another toon and post them on the AH or in Trade.
This strategy works well every time new craftable end-game items appear in the game whether it’s an expansion or just a patch. You just have to prepare for it, or be willing to track down some help. You have to spend money to make money, as it were.