This started out as just a triangle gift box to exactly fit a gift I have for my wife.  Once printed, I saw the potential to dress it up as a tree, so I did just that.  

While this will work perfectly if you buy the same exact gift, it should still work quite nicely with any small gift, perhaps with some tissue paper in the corners if needed.

Nothing fancy in the orientation or printing.  For one ornament I did use the color change feature in Prusa Slicer.  I printed way more ornaments than I eventually used, but those are super fast prints (about 10 minutes for a set of 4) and I had a lot to pick and choose from.

I designed the top and bottom with a .5mm gap between them which is more than enough.  The fit seems quite nice while not overly tight.