I saw the Rubik's Companion Cube "Stickers" by twisteddream13 and thought that the design would make a great trinket box.
I have taken inspiration from the design and recreated it as a solid side. Print it out 6 times and glue 5 of them together along the bevelled edges. Leave the "lid" loose and you have a handy dandy companion cube box for all your secret stuff.
- Added an actual lid *
Again, Same settings as the sides, No support needed
I printed this in Grey PLA and as long as you have good layer cooling you shouldn't need any support