Usually it's best to avoid a lot of instance runs. It is too difficult to account for bad groups, and some instances are too far away with too few quests. Since the experience is very good, it's a good idea to clear nearby instances which have a lot of quests once (Gnomeregan, Deadmines for Alliance). Distant instances with few quests should be avoided (Deadmines for Horde). Low level instances can be cleared by paying or befriending a single high level character. However, since patch 3.3 a new Dungeon group finding system has been implemented, as well as a direct port to dungeons (when entering the group you get ported to the dungeon and back to the same location if you leave it) and thus the travel time to dungeons has been greatly reduced. This makes it a good idea to complete quests or grind while you wait for a group to become available.
I've used WoW-Pro for years and in WoD, Legion and now BfA it's been awesome for just going on auto-pilot and working your way through a zone. It has 3 levels of depth you can set, so you can set it to just do 1) the main story, main points of interest and rare mobs and treasure that aren't far off the beaten path; 2) every quest with a more thorough dive into the side stuff; 3) absolutely everything.
Professions: This may seem strange for a leveling guide, but the first opportunity you get, pick up both the Mining and Herbalism gathering professions. Not only will this allow you to track many various quest objectives on your map, but you also get a fair amount of experience whenever you gather. I'd put it at around 10% of a quest turn-in per gather. Since most of your wasted time in WoW is travel time, stopping to gather ore or herbs can keep your exp/h rolling as long as you don't go too far out of your way. You should only gather if it's convenient, and on the way to an actual quest objective. Don't make gathering your priority.
EXCEPTION: If you have Mining and only use Jewelcrafting to craft stone statues (for additional in-combat healing), then this may be a useful tradeskill. However, like Engineering above, it should not be a leveling focus and should only be used to assist with power leveling. Doing any more than this will become costly and should not be undertaken during the power-leveling process.
Despite the fact that World of Warcraft still relies on the old 14-year-old game engine, the game can cause some frame rate drops even on newer hardware equipment. So we've decided to devote a lot of time and space to answer such questions like: How to set up the graphical options? What should I do to make sure that WoW runs smoothly? WoW's hardware requirements have evolved over the years due to graphical improvements, so find out if your computer can handle the highest graphics settings of the game.