Starting to add some of the Geocache Containers that I've "created" over the years. Usually, what I do is take a object that I've found on Thingiverse and meld it with another to make it a container. My container of choice that I use when doing this is usually https://www.thingiverse.com/thing:268498.
I printed with PLA and used 20% infill. You can use different resolutions and infill and get a pretty good print from this model.
Like most of the stuff I print, it was painted with acrylic paint and then coated with a Krylon spray to help protect it from UV and water.