Page 55 of my comic/webcomic/graphic novel series, Six-Petal Pyramid, shows one of my original characters having a contemplative moment in his high-rise office. This is his private collection of artifacts.
As with the rest of my comic pages, I make my environments in Google SketchUp first, then trace and otherwise modify them with Clip Studio Paint EX.
Sometimes I make props from scratch, and other times I download materials from the internet to use.
Some 3D assets, such as the sarcophagus, are placeholders for the totally different designs that you'll find in the final product.