I'm a big fan of 3M Command Strips. The let me mount light weight things, like Apex modules, to surfaces without having to drill into the mounting surface. With this design, I've been able to mount and then reposition my modules as needed as I expand my Apex system.
Please be sure to clean both the printed surface and the mounting position well before applying the Command Strip. In my experience, failing to do so is the largest cause of premature adhesive failure.
Parts:
The author marked this model as their own original creation.