By display cabinets do you mean like a kitchen sideboard? Like a cupboard at the bottom with shelves above?
I’ve seen some very simple but effective cupboards made out of a jenga block with card doors glued on the front. I’ve also seen and made some bookshelves using lollipop sticks for the sides, back and shelves. I’ve never seen the two combined, but you could do a sideboard style display cabinet using a jenga block cupboard below with a lollipop stick shelving unit on top.