I just finished this fun little keeb which I based off the Hummingbird, but I made it hot swappable, dropped the pinkies down more, made the thumbs more reachy, and spaced it for Chosfox CFX keycaps (tighter than standard Choc spacing).
It has a top plate and sound-dampening silicone gasket, as well as foam on the backside of the PCB.
Everything is open sourced on my github
The classic resource is ai03’s guide, successfully used it myself a couple years ago to design my current daily driver in KiCAD.