All credit goes to AlmostAussie over at printables for the great design. The text below is theirs.

Outline:

This is a remix of my Heavy Duty Bag Hook. The model is the same but has a greatly increased surface area for adhesive tape. I wouldn't necessarily recommend this for heavy bags, but the model is optimized so that the pressure of the weight on the hook is well distributed. Strength of the hook will depend on the type of your adhesive tape and the surface you are mounting it onto.
 

Print Suggestions:

The model is designed for zero supports and optimal strength. Use the orientation in the 3D files. I suggest you print this in PETG or ABS, but it should be totally fine in PLA.

I would use at least 5 walls with 25%+ infill.
 

The back of the mount is recessed by 0.5mm so that the hook does not appear to be floating off the wall as much.

Hardware:

I would recommend something like 3M double sided foam tape.