This is also the reason why when I read in WoW forums of people skipping guide sections, due to being too low level I'm not agree and start ranting about it: it'll be a mess syncronizing with the guide and I've seen many people complaining about missing quests or accusing the guide for being innacurate, but not realizing that was their fault since they're skipping and missing a lot of quest chain requirement. Of course this apply if you're following a guide, believe me, it's very frustrating when you remain stuck in a guide section due to the reasons I've mentioned, more than doing grey quests (but they allow to be perfectly in sync with the guide) and goiing here and there to get the pre-requisite quests.
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.
Auto looting a mob will increase leveling speed for the expansion. to enable it = Esc, Interface, Controls, Enable Auto Loot. I'm including this because sometimes the simple things are missed. I, sadly, went 3/4 of the way through WoD not knowing that hitting the space bar for my mission tables is much MUCH faster than waiting it out. (i never claimed to be smart OKAY) =P
I defintely think at 118 you should go and do all four of these parts. These are required to unlock World Quests and probably take about 60-90 minutes to get through. If you do these whilst levelling (especially all in one go at 118) then when you hit max level you're ready to go on WQs. You can go finish the zones quests at your leisure over the next weeks/months or never even finish them if you don't care about questing.
You can skill up your fishing from 1 to 150 in any fishable water in Zandalar or Kul Tiras. Go to the nearest water, find the fishing skill icon in your spell book (P) at the profession tab, drag this icon to somewhere on your action bar. Stand in front of the lake/river and press the fishing button. Mouse over the lure in the water, and when it splashes, right click on it.
Most of the time you spend leveling will involve questing and slaying monsters, but there’s also a lot of travel. Travel earns you little experience (you do gain a bit for discovering new areas), so it’s wise to keep travel to a minimum. The new level scaling system, which scales zones to your level within a preset range, helps with that. You can choose what zones you want to experience and stick with them until you finish their quests.
This gold making advice is applicable to most players, except if you are an enchanter, in which case there is a very strong case to turn them into dust and essence for your profession needs. As an advanced tip, you can explore the use of mobile apps that let you post on the auction house at the right time because the price of greens tends to fluctuate rapidly, and could mean a large loss of potential gold income.
Full disclosure on my time with Battle for Azeroth thus far: I leveled a Horde character to 120 and completed all three Zandalar storylines plus put about 20 hours into end-game content. I have also leveled an Alliance character partway through Kul Tiras and completed portions of the Stormsong Valley and Tiragarde Sound storylines. My only experience in Drustavar has been through the eyes of the Horde thus far.
Although WoW currency can be found through quests, fallen enemies or the dreaded "farming" process, doing it the conventional way is time-consuming. Considering the upcoming release of the Legion expansion pack in August of 2016, stocking up on gold is more important than ever. This way, you can spend less time farming and more time buying everything you need to tackle the next set of challenges.
In addition, you'll want to pick up leg and shoulder enchants and have them in your bags. These enchants have a level requirement of 80/85, but can't be placed on items above iLVL 136. You can get around this by having a level 85-100 character apply the enchant before mailing it to the character you're leveling, thus getting use of the enchants before level 85.
There are also numerous gold-making guides available for World of Warcraft players. Currently mmobux recommends Killer Guides' World of Warcraft Gold Guide, which covers a broad range from daily quests and professions to making gold while leveling and auction house trading. 'Standard' farming spots are covered as well, making it an interesting resource for bots as well. Yielding up to 500 gold per hour, the strategies are suitable for players of all skill levels. If Killer Guides keeps the guide up to date, it probably will become a valuable resource for professional farmers as well. There also seems to be a German-language version available: WoW Gold Guide (German)
The community was apparently frustrated with Blizzard for a lack of communication concerning the issue, but it looks like that was due to the fact that their heads were down as they worked to understand the problem. It was explained that they didn't want to just roll out a quick bandage, as that would likely cause unforeseen issues down the road. Instead, they're crunching the numbers and digging into the code in the hopes of discovering a legitimate source of the problem.