I made some pinhole cameras last year or 2 years ago from toilet roll tubes and used medium format film. The results were really interesting. You could literally see the shape of the pinhole. The 2nd one I didn’t take, my girlfriend took it to give her the credit. The only tips I can give you is to experiment and have lots and lots fun!
I made a pinhole for my Canon 300D (am I allowed say that in the Film section???) and got shots like this
I recently got a Daylab 3X4 Pinhole that takes Polaroid pack film. I haven’t really had a chance to take it out for an extensive spin yet but did take this one shot to test it out.
I made one of those matchbox pinhole jobs last summer. Great fun, you’ve got to experiment with pinhole sizes though, it’s difficult to get it right with a 10mm focal length: