Screwing in a flat head screw hook can be challenging since convention tools like screw drivers can often not be applied. With this jig, the hook can be screwed in with a socket wrench, which is much more convenient, especially in situations where there is not a lot of space.

This model is for a 30mm socket and a 10mm slot, which fits hooks that are between around 6-9mm. The better the hook fits, the better the jig works. I've added a FreeCAD file, so the jig can be customized for different sockets and hooks.

I've printed my version with PETG with 5 perimeters and 50% infill. However, PETG is too soft so the jig gets deformed after couple of usages. If you have access to stronger material like ABS or ASA, it might last longer. Maybe even PLA might work better as it is more stiff. Let me know about your results in the “makes” section.