Be aware of the seasonality of items. Check what items are used in seasonal achievements, such as Delicious Chocolate Cake or Small Egg during Children's Week. When the Darkmoon Faire is in season, Darkmoon cards and decks (Furies, Elementals, Lunacy, etc.) tend to sell well, but prices also tend to get depressed. When the Faire leaves, prices return to normal, but sales volume decreases. The same is true of things like Snowman kits, Red Holiday wear, etc. Holding onto that Snowman kit for a few months, and then listing it in July, can net you a significant profit.

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.
You can earn a decent amount of XP by doing Herbalism or mining. Any zone works but I prefer Sholazar Basin as a lot of the mobs are not aggressive and the mobs are spread out so you will find a lot of herbs and ore that you don’t have to fight for. It is possible to make about a level every hour by doing this, or a level every 30-40 minutes with rest XP.
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.
Back in the days of Burning Crusade, leveling up your character was a very tedious procedure. The quests were not even shown on the map, you always had to read through the quest list and figure out where to go and what to do (which mobs to kill, items to retrieve, etc.). After a few more expansions, questing became a little bit easier, due to the quest chains being more linear. You can pretty much follow the main quest storyline. Also, the map became more interactive.
Island Expeditions:[5] 3-Player co-op with optional 3v3 gameplay. Players will explore uncharted isles across the Great Sea. There is azerite and other unclaimed resources bubbling to the surface that is highly sought by both factions. Complete varied and dynamic objectives with a large variety of challenges to overcome. Race against advanced AI opponents designed to thwart players using tactical and strategic moves that consistently change. Optionally, players can choose to race against other players, creating a 3v3 PvP environment. 
What’s worse, it’s rarely satisfying when you do make it to a new milestone in your grind to unlock the gear you need. Legion had legendary items that changed the way an ability functioned, which would also completely change the way classes played; the Azerite traits in the Battle for Azeroth are rarely as interesting. Instead, they are simply passive bonuses that, in most cases, help you do more damage without any extra effort on your part. While some classes are lucky enough to have traits that change their gameplay slightly, Blizzard has so far seemed to favor nerfing those traits out of viability for most specs.
Awesome trick really.  In this farm we'll be taking advantage of game mechanics to exploit a way into getting more defias loot drops.  The defias leggings and gloves have respective selling prices of 3,000g and 14,000g and only drop from 1 mob in the instance a staggering 1% of the time.  But do not fret, we can get the upper hand on this.  Much like past drop-combat farms, if you kill just one of the two defias overseer's in the instance, THEN drop combat, the one you killed will instantly respawn.  The trick here is to bring a character that can consistently drop combat and score many more kills than the average farmer.  To date, a hunter is best – with night elf being slightly better because of shadowmeld.  You can also bring potions of invisibility to boost the effect.  Anyway, while the average farmer only gets 1 shot to get these super rare xmogs, with this method you can get up to 40 chances in an hour.  Seems fair right?
This level range opens a variety of zones from the Cataclysm expansion, which are spread across the game’s original continents, but it’s more efficient to head to the continent of Pandaria. You can spend the entirety of this level range exploring its uniquely themed zones and quests. The Jade Forest, Valley of the Four Winds, and Kun-Lai Summit are our picks, but all the zones are worth checking out.

Time Trials for MDI take place during a 72-hour window on the Tournament Realm. The first Time Trial window begins Saturday, March 23 at 7 a.m. PDT for MDI West (North America, Latin America, and Europe), and Saturday, March 30 at 7 a.m. CST for MDI East (China, South Korea, Southeast Asia, Taiwan and Australia/New Zealand). When this time window begins, players on the tournament realm will receive a quest with three Blizzard account-bound keystones from this Turnip, found in Hook Point (Alliance) or Mugambala (Horde).
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