You can have a maximum of 25 quests on 1 toon. Starting fresh (0/25 quests) on a toon will be beneficial at the start of a new expansion. ahhhh a fresh start. On the flip side, stocking up with 25 completed quests, ready to turn in, might be beneficial too. As soon as BFA launches, turn them all in for a great small boost to EXP before you even step foot into the new land.
Take breaks. Unless you're straight up no-lifing it over a weekend or something, this leveling process is going to take ~40 hours. But any time you do need to step away, log out. That tiny little bit of rested exp is insignificant...but you never know when something might come up and you'll have to leave for a longer period of time than you expected. Better to be logged out and safe(especially with War Mode on) than AFK waiting for a d/c. Plus, you'll need to stretch, eat, shower, and maybe sleep. XD
Gathering nodes need to be fixed. Herbalism and mining give small amounts of experience as you level, mostly rewarding you for going out of your way to gather nodes. A change a while back makes them scale naturally with your skill level, so that you can mine or herb anything, anywhere, just getting varying amounts of usable fragments or whole items depending on your skill.
First: Azeroth Auto Pilot is a fantastic addon for those who just want to get the leveling done and have 0 desire to read text and watch cutscenes. I have submitted a lot of feedback to the developer over the course of its creation and after doing a play through on both Horde and Alliance I can strongly recommend this addon. For those who want to watch cutscenes, I am somewhat positive that there is an option to not skip cutscenes. I strongly recommend trying this out once BFA launches because even if you don’t skip the cutscenes the proper pathing and skipping of quest text will save you a lot time. I would like to note that the only zone where I encountered an issue was in Vol’dun where the pathing seemed a little off from what would make logical sense, but I have submitted that feedback to the dev and hopefully he has corrected it. THIS ADDON IS COMPLETELY OPTIONAL AND IF YOU DON’T WANT TO USE IT YOU DON’T HAVE TO. IM JUST GIVING PEOPLE INFORMATION FOR THOSE WHO LEVEL ALTS/HAVE PLAYED THROUGH THE STORY BEFORE/OR JUST WANT TO GET LEVELING DONE ASAP.