At heart a simple cylindrical screw container, but pimped up by lots of knurling options.

Customizing:

• Download and install OpenSCAD, it's completely free (open source; Win/Linux/Mac),
• run it and load the scad file,
• customize parameters (on the right panel),
• don't forget to check the “for printing” option,
• press F6 to render, then F7 to export STL.

I wish Printables had a an OpenSCAD customizer!

Printing: 

I recommend splitting into objects and slightly different layer height for body and lid (e.g. 0.20mm/0.17mm) for smoother screwing.

I also like to use octagram spiral bottom infill.

Edit: As of a request, I added a version that allows a string to be attached to the lid. This takes away some inside space, depending on desired string diameter. This is a new SCAD file; you need to use OpenSCAD to use this option.