I live in an extremely humid climate, and this is by far my favorite storage solution to keep my filament dry and ready for printing. Props to Stephen Wardlaw for the basic concept. I've taken his design idea and tried to improve on it in a few areas.

All the parts here are designed to print without needing supports in the orientations that you'll find in their STL files, with the exception of the base piece that does need supports. I've included a pre-supported version of that STL, and that's the version I prefer and recommend. The filenames include a print count (_x2, _x4, etc) where multiple copies of a part are needed.

An assembly video is available on my YouTube channel: 

In addition to the printed parts, you'll need the plastic cereal containers and a few bits of hardware. The items that I used all came from Amazon, and I'll leave those links below:

For those who are curious, the total cost per dry box for me (including the Amazon items listed above and the filament needed to print the parts) is somewhere between 8 and 9 US Dollars. In my studio, where the humidity is almost always above 50% and often closer to 60%, these dry boxes are able to keep my filament in the 10-15% humidity range.