Have you checked out Cyclic Dungeon Generation by Sersa Victory?
I’ll let her describe it: “Cyclic dungeon generation is the name given to the level creation algorithm in Joris Dormans’s 2017 roguelite Unexplored.Taking inspiration from games like The Legend of Zelda, this algorithm generates dungeons by composing together cycles: circular loops of linked dungeon rooms designed to create a specific flow of gameplay. There are several types of cycles that can be used to construct a dungeon, such as lock and key or hidden shortcut.By nesting multiple different cycles, a dungeon can be generated that feels more like a human being intentionally designed it, rather than a purely random scattering of chambers. This document attempts to adapt Unexplored’s cyclic dungeon generation algorithm into a process that can be used to quickly create engaging non-linear dungeons for tabletop roleplaying games.”
Becomes…
^images from https://sersavictory.itch.io/cyclic-dungeon-generation
It’s a free PDF that has great advice for making some killer dungeons. I’m using it to prep for a session this week and I am totally pleased with the result so far. 
Have you heard of it? Have you tried it? What do you think?