For my first custom build, I wanted to do something that needed to be produced to specific measurements.
After a couple of rounds of prototyping to play with dimensions and strengthening, I present my door hook.

It fits my 45mm doors with 2mm clearance on top, and has been tested to 5kg without issue when printed at 0.2mm layers using PLA.

There's a small hole on top for fixing in place, if desired, but I haven't felt the need to.