A good example of adapting existing material to suit your purposes when making custom monsters.
Plot Basics for Dungeon Masters: Complications and Obstacles
A Guide for New Dungeon Masters to Making Simple Dungeons in Fifth Edition DnD
Setting out to run a game of Dungeons and Dragons for the first time is a daunting task. It’s really difficult to know where to even begin!
…what does a “good” Dungeon Master look like? It’s hard to pin down specific qualities, but I can list what I see as virtues to aspire to!