I tell you my experience. I'm leveling a priest that it's 60 now and since I have also done some instances (and I have full heirloom set with 20% experience gain bonuses) and been very ahead of the guide, I skipped some zones since they were grey quest for me, well it was a real mess. Missing quests because I didn't to the previous to enable the following. Going in a zone then realizing that I couldn't do that quest because I didn't do the starting quest chain, very unconmfortable. In short what I suggest you it's not to skip areas, or make really sure that you do all the quests required (at least) and check carefully the previous zone you'll going to skip to make sure that you won't have problems with struggling finding where to start the quest chain to sync with the guide section.
Swim Speed Potions (used especially at lvl 37 for Faldir's Cove in Arathi Highlands and lvl 57 in WPL). Try to get multiple stacks of these. I also recommend keeping a stack of these always in your bags. You will frequently pass rivers and lakes and can use these potions to pass them faster through out the guide. Please note that these potions do not stack with Druid's Aquatic Form and Glyph of Aquatic Form.
A farm that I myself made drastically popular about 2 years ago. This farm is a simple pet and transmog spot that requires you to pull the entire wailing carverns instance. Besides how it sounds, this farm is VERY easy going and can literally be done while you watch something else entirely. (netflix maybe?) While it's not as potent as it used to be, it still has some merit in it, especially if your server is low on the deviate hatchling pet. While it does take some time to drop, I can usually average a deviate hatchling every 30 minutes or so. However, since I released the video on it, the price of the pet has dropped wildly.
ClickBank is the retailer of products on this site. CLICKBANK® is a registered trademark of Click Sales, Inc., a Delaware corporation located at 917 S. Lusk Street, Suite 200, Boise Idaho, 83706, USA and used by permission. ClickBank's role as retailer does not constitute an endorsement, approval or review of these products or any claim, statement or opinion used in promotion of these products.
Just before Battle for Azeroth goes live, you will want to log all of your characters out in the zone of Silithus so that you can acquire the quest to talk to Magni and obtain your Heart of Azeroth (refer to our Heart of Azeroth guide for more information about this item). This is the new artifact-type of piece of equipment that you will use for all of the Battle for Azeroth expansion. Once you acquire your permanent neck slot piece of equipment, get back to Stormwind or Orgrimmar to begin your scenario that leads into the introductory areas of Kul Tiras and Zandalar.