A while ago I backed the Kickstarter for Questing Beast Ben Milton's update to his simplified OSR RPG, Knave, but I've only just got around to reading the PDF through. It is rather good.
Knave 2e is certainly not a simple product, a very great amount of thought seems to have gone into every page. Both design and content. It does however cut away a great deal of the chaff to leave an elegant set of rules and concepts that should give a really enjoyable game with a focus on old school exploration.
To brush up on the my DM tips, and campaign design knowledge, I've also been watching some of the many YouTube D&D channels, especially those related to Sandbox Campaign design and DMing advice.
Here is what I have found so far:
Questing Beast - all the latest from the OSR scene, plus Ben's excellent analysis on game design. Including these on Dungeon Crawling Rules, Nine Dungeon Design Secrets, Building Living Dungeons, and how to Stop Hiding Traps.
Matt Colville - the daddy of YouTube DMing advice, there is something for everyone here. Matt's take on West Marches and Sandboxing brought the concept to a new audience. This one on Dead Empires, the time abyss, and an endless decline is interesting too.
The Alexandrian - an extension of Justin Alexander's excellent blog advice
Master the Dungeon - Lots on traps and game design. The videos on using Metroid and Legend of Zelda for dungeon design were interesting, as well as this one on using resources as keys.
Bob World Builder - Bob's infectiously cheerful approach to world building
Dungeon Masterpiece
- another lighthearted and entertaining, but often thought provoking,
look at RPG DMing and Campaign building. Here is the Baron's take on
the Super Metroid approach and Random Encounter Tables.
Dungeon Craft - Professor DM has lots of great advice, I especially loved his B4 - The Lost City play through video.
Loki's Lair - has lots of game advice including a great video on using a hex flower for weather.
Map Crow - great stuff on designing and drawing maps
Trekiros - a new channel with an interesting video on Random Encounters.
Yinka - discusses world building concepts, including mistakes
Ginny Di - a more new school D&D channel but with lots of good ideas, high production values and a fun presentation style.
Dicebreaker - a more general gaming channel than the others but their OSR and OSE episodes were good explainers for the un-initiated new school players.
On Tools, there is this video from LoreTeller and a link to their resource web page.
Hexcrawls, Hex Maps, & Sandboxes Hexed Press PlayList on YouTube
How to Hexcrawl GFC D&D goes through the process they use.