When you have completed your third zone, you should be nearly max level, but you still have work to do! Head back to your faction hub and complete the last foothold quest to unlock your fourth mission table champion. After, you will want to do your newly available invasion missions for your faction. This quest chain is one that will be time gated by reputation levels earned with the 7th Legion for the Alliance and iThe Honorbound for the Horde. Complete as many quests as you can and then finish up your leveling with side quests you may have left in previous zones as necessary.
M Madmortem Alliance Madmortem Horde Magtheridon Alliance Magtheridon Horde Mal'Ganis Alliance Mal'Ganis Horde Malfurion Alliance Malfurion Horde Malorne Alliance Malorne Horde Malygos Alliance Malygos Horde Mannoroth Alliance Mannoroth Horde Marécage de Zangar Alliance Marécage de Zangar Horde Mazrigos Alliance Mazrigos Horde Medivh Alliance Medivh Horde Minahonda Alliance Minahonda Horde Moonglade Alliance Moonglade Horde Mug'thol Alliance Mug'thol Horde
Something to keep in mind as well is that this will make enchanting materials more valuable, since it is likely most players will now simply scrap their boe greens instead of getting them disenchanted. Also redundant dungeon/raid gear can be scrapped rather than traded to the (guild) enchanter in the run. Less stuff gets disenchanted, meaning there will be less ecnhanting materials, meaning their value will rise. All the more reason to DE rather than scrap as an ecnhanter.