Hazzikostas said his top recommendation prior to the BfA prepatch would be beating the Mage Tower challenges for those special artifact appearances. Not only are those some of the most attractive weapon skins in game, but the Mage Tower challenges will be going away when the prepatch hits, so you've only got a couple of weeks left to complete them.
If you want to spend as little time on your alt as possible - just do Legion Invasions. You can use sites like (https://wow.gameinfo.io/invasions) to track when the next invasion will be. Log in, fly to the closest world quest, and once there - right-click on the quest's name in your quest log and "Find Group". Sign up for some group, or if there's none - just start your own immediately, and people will come to you. It is 10 times faster to do invasion quests in a group. Once that particular quest is complete - leave the group, and fly to the next one, where you should find another group. Don't expect the group from one world quest to follow you to the next. Then you simply log out until next invasion. You can do 1-2 invasions a day, and each invasion will give you about a level or 1.5 of experience, if you have full heirloom gear. Each invasion will take about 20 minutes.
Despite all of these problems and this laundry list of glaring systematic issues, the crowning achievement of Battle for Azeroth’s endgame is that it still remains enjoyable all due to those two pillars of raiding and dungeons. That won’t last forever. As the expansion goes on, and the grind necessary to progress becomes even more demanding and the time spent in content that simply isn’t fun increases, it will be harder and harder for raiding and Mythic+ to carry the expansion along.
Dark Iron dwarf - "Known for their fiery tempers and fierce determination, Dark Iron dwarves have a turbulent history with the other clans. A failed coup in Ironforge ignited the War of the Three Hammers, and many of the Dark Iron once fought in the service of Ragnaros the Firelord. Though one faction is pledged to Queen-Regent Moira Thaurissan, others refuse to stand alongside their kin. The Alliance seeks a united Dark Iron clan to harness the power of Azerite and aid their struggle against the Horde."
Plus, I am a pet collector, and there are plenty of pets to collect in the new dungeon. Completing the dungeon’s challenge mode grants players a Mini Spider Tank battle pet. Continue playing on a weekly basis to earn currency towards items like the Unopened Gnomeregan Supply Box, Mechanical Cockroach, Schematic: Mechantula, Leper Rat Tail, and Rechargeable Alarm-O-Dog Battery.
If you are just coming out of Level 110, you will probably have a number of different Legendary items to choose from. Your Legendaries' special effects will stop working at Level 116, but until then they can be a very powerful addition to help you level up quickly. These are our Legendary recommendations for leveling as a Fire Mage in Battle for Azeroth:
No matter your experience level—whether you’re about to experience the thrill of hearing the Stormwind City theme as you walk through its epic gates for the first time, or whether you can spell Ahn’Qiraj off the top of your head—here are some tips and suggestions for making the most of your new life in the World of Warcraft (or your epic, Illidan-like return to Azeroth.)