I made this simple hook because i needed something to snap onto the shower door. The hook is made to snap onto a bar 26mm wide, but you can scale it up and down according to your own needs. I printed this using cheap PLA, 0.25 layer height and 20% infill. Add infill or set perimeter thickness according to strength needs. 

I've included .gcode for printing this on a Prusa Mini as well as the .3mf file