One of my favourite pastimes is taking pictures. There is something about grabbing my camera and heading out for some street photography.
I got my first camera when I was 16, a very long time ago. Over all those years I have built a very large collection on lenses. Keeping all of that glass organized is a challenge in it self.
In the past, I would put a piece of masking tape on the lens mount cap and identify the lens with a magic marker. This made it real easy to grab the lens I needed from my bag. Not a really elegant solution, but one that works.
Thingiverse user M600 has come up with a great solution: A fully modular lens mount cap solution for DSLR cameras.
He came up with a 2 piece design consisting of an inner part that matches your lens mount type and an outer part which identifies your lens. He provides a massive selection of outer parts for various prime and zoom lenses and creating one that isn't listed can easily be done with CAD software like Fusion 360 or FreeCad.
Simply print the two parts and slip the inner part into the outer one. Drop a bit of CA glue between them to keep them together. The last thing you want is them coming apart when reaching for your lens and having it drop to the ground.
I printed the inner part in black and the outer one in yellow. This makes the lens size numbers easy to read. It has transformed the way I organize my lenses, makes it crazy easy to find what I am are looking for.
While you are at it, 3D print yourself a hot shoe protector to protect the contacts on your hot shoe.