For larger prints I would suggest REALLY long hangers so the prints or pictures etc. will hang far enough out from the wall so they will lay flat.
You can also try stenciling or Vinyl decals!
Perhaps hang a quilt or tapestry on it.
Hello Nana, you can hang framed pictures on it, you can scatter them or arrange them neatly, you could hang a nice tapestry, use lots of textures
Depending on the length of the wall, what about putting a spring tension curtain rod or a long metal pipe from one side to the other?
You could use "S" hooks to hang picture frames from it.
My Aunt used to talk about the time her family had been stationed in Guam and having to try to decorate arched Quonset hut walls.
No matter what she did, it didn't look right.
it all depends on the room ... It may be shelf , vignettes, https://www.pinterest.com/pin/716213146970861515/