The IKEA Tjusig hat rack is a very practical and nice looking thing. I bet it is used millions of times worldwide. I also use three of them in different places. One thing I always wanted is that there were more possibilities to hang something on a hook. Especially in the cold/wet season to dry a coat or alike.

So I made a hook that "clicks" in the rails of the hat rack and can be placed freely all along them.

This is a double sided hook but I also uploaded a single hook version.

For most uses PLA should be strong enough but you can also try PETG.