I'll agree with Sly about small prints. 4x5 alt prints can be exceptionally beautiful. I have also made 6x6 and 6c7 (120 film) carbon prints and platinum prints -- as well as from a Diana camera.
That said, I have a couple 11x14 carbon prints in the wash right now (and a couple 4x10 and 8x10's).
Another possibility -- panoramas made of two, three or four 4x5 negatives (either vertically or horizontally placed).