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.
Players have ever thought that Warfront are one of the most important and anticipated feature. Warfronts are a 20-man, PvE, large-scale cooperative mode meant to represent the large-scale war on the homefront, as members of each faction fight for control of a location critical to their war efforts. But now the Warfronts seem less worth players' attention.
There are several reasons why this may have happened. First, only a fraction of the players who interact with the auction house buy or sell WoW Tokens. While the value of both gold and commodities plunged relative to real money, the value of gold and commodities remained steady relative to each other. Players who didn’t interact with the Token market could buy the same number of flasks by doing the same amount of world quests, or selling the same number of gems or enchantments, so these sellers saw no reason to raise their prices.
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.
Once characters reach the level cap, gameplay turns from leveling to the end-game. This represents the culmination of the leveling process and the beginning of the deeper challenges awaiting max-level characters. While play prior to this point is oriented around accumulating experience and gaining new skills, the end-game represents the polished 'final destination' for players, at which characters are fully developed and ready to tackle the biggest challenges in the game, or to relax and make their own adventure.
Excess Potion of Accelerated Learning: Acquired in your Garrison (part of the Warlords of Draenor expansion), this gives you a 20-percent bonus to experience from killing monsters and finishing quests. It lasts one hour, but you can buy it multiple times and use it back-to-back. Alliance players buy it from Sergeant Crowler, horde players buy it from Sergeant Grimjaw. Does not work above level 99.
I made one for my guildies but its for the Horde leveling process. One tip that goes for both factions is that you dont need to do all 3 zones to hit 120. I did like 1 and than three quarters of another. But once your 120 you need friendly with all 3 of your factions new reps to unlock world quests so make sure you hit at least friendly with all 3 while your leveling.