I didn't like the other mounts for the Philips Sonicare toothbrush, so I made my own. It comes pre-supported (.2mm gap) and you will have to modify the file if you dont want the support, but it removes cleanly.

The back has a recess to allow affixing double-sided 3M tape (the green checker pattern type). Going on almost a year now without signs of loosening in a humid, damp bathroom.