Return of the Lazy Dungeon Master is in my opinion basically what the DMG should be. It’s an excellent guide to, basically, not just the rules but how to run an excellent game. This topic is not covered in the DMG with any effectiveness, which is kind of weird when you think about it.
The DM Lair is also pretty good in my opinion, in-depth videos with a lot of experience and insight behind them. It’s particularly good if you’re dealing with one specific type of problem or situation you’re trying to approach better in your game. There’s probably a video about it.
Also, bin the DMG treasure rules. They make no sense. If you’re playing a module, then you’re okay, but if you’re doing homebrew I would recommend just abandoning 5e’s economy and using the Pathfinder 2e economy instead or something. I tried 5e’s tables and they were bad, I tried rolling my own guidelines and the result was also bad, IDK, if you figure out a good system, let me know.