Are you looking for just the right door hook but can't find it? So was I: our current apartment has doors with an unusual width, so all store-bought door hooks we have won't fit. I couldn't find something that fit exactly on Thingiverse, so I decided to create a very simple parametric design, which should fit on any door!
Just plug in the numbers for your door and you're good to go. As a bonus, you can add more than one hook (so you can hang several things separately), and you can choose the hook profile (a simple, slightly easier to print profile, and a rounded profile but with still limited overhang).
Update 6/15: Added minor tweaks that may help flex and fit (hook buttress option, and slightly off-perpendicular door hook backside); updated rounded version sample to reflect new options.
Update 6/13: Separate front and top/back thickness settings.
Measure your door (thickness and gap between frame and door), and generate a hook. The sample STLs are for my funky door (too thick, and with a tight gap) -- you probably want something narrower and slightly thicker (strength never hurts, if it fits).