I’ve some projects where I want an enclosure, but need to get at the innards frequently. I gave up on screws, and don’t know enough SCAD to do interlocking tabs, so I went with magnets. The capacitive relay setup is a good example. Four 6x2mm magnets — two glued to the bottom, two to the top. Holds the top on great (even upside down), yet easy to pop off. And, if you’re really nutty like me, flip the mirrored magnets around so that the top only snaps together one way. I use E6000 or similar for glue.