Get organized and reduce the clutter with either of these SD card holder designs.
Whether you just use standard size SD cards or micros as well, these compact "button" designs fit easily in any desk environment. They're also stable enough that you can swat them around without tipping them over. The slots for the cards are well proportioned and can be printed to provide a snug fit while allowing easy removal when a card is needed.
You don't waste as much time cleaning up if you're already organized.
If you want to tighten the fit and you use Simplify3D, you can increase the extruder's 'extrusion width' or even increase the layer height or some other means to increase the roughness of the surface texture. Of course, you'll want to do the opposite if you want to loosen the fit.