Within the context of Classic, the method most frequently proposed is to re-tune bosses to make them harder. Rather than copying the numbers, re-create the relative difficulty. Kind of like, when you first start working out, you use small weights. When you get stronger, you lift bigger weights. The WoW community is more knowledgeable, more experienced, has better hardware, etc. We're "stronger." So give us tougher bosses. There are a lot of forms that could take. Bosses were constantly re-tuned during vanilla anyway, so if Ragnaros does 10% more damage or something, is that really a problem? I don't think it is. What about resistance gear? back in the day, collecting resist gear was a thing people did. But the numbers and strategies are so well known today that only the tank really needs it anymore. Bosses could be re-tuned with more resistible elemental damage so that's important for entire raids to gear appropriately. That would be entirely keeping with the spirit of vanilla even if the actually numbers sitting in a database somewhere were different than they were ~13 years ago. If you want to go a little farther, a few people have proposed adding new abilities to old bosses, adjusting their timing, etc.
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.
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.
There are two parts of the quest chain for each continent. The first part involves defeating numerous Master Pet Tamers, and the second requires you to triumph over the Grand Master Tamer. After you've bested the Grand Master Tamer, dailies from each Tamer will unlock for that continent. All the dailies continue to reward experience for your companions, however only the Grand Master daily quest will reward the Sack of Pet Supplies.
Bonz has the upper hand, as his Zombie-Type monsters gain a 30% ATK and DEF bonus because of the Graveyard Field, and when they are destroyed, they just regenerate, and become even stronger from "Call of the Haunted". However, when Yugi and the gang arrive, Joey manages to figure out the Zombie's main weakness and that is their DEF is 0. Using "Shield & Sword" to switch their ATK and DEF values, Joey wins the Duel. Bandit Keith then locks the gang in, double crosses his three companions, and enters the Duelist Kingdom Finals after taking Zygor and Sid's five Star Chips by force.
Hey! Just came back from the game, looking to play bfa but i had no idea what to do when i logged on. It was all a bit confusing and i know nothing about the current content. So after some frustration i bought zygor again (haven't used it since cata ..) and i do currently feel more comfortable. I'm following the guides from the 'suggested' tab in zygor but i'm just really unsure if what i'm doing is even relevant. I know the end of the expansion is coming so i'd hate to waste my time. OK i will list the things it's been telling me to do.
With the Classic beta now out it seems every related article somehow manages to spark the eternal war of "Vanilla was the best WoW sucks now" and "lol nostalgia goggles, Vanilla sucked, enjoy your two weeks of Classic". I have to say, even though I understand the principles behind the battle and the reasons people behave and talk this way... I actually REALLY don't get it on a deeper level.