1. Why not hang art on a door? From House to Home.
2. I love the idea of hanging art on a column that's just a tiny bit narrower than the canvas. Rules were made to be broken. From Sketch 42.
3. Hanging pictures in front of a bookcase makes an interesting, layered look… provided you don't read those books much. From stlmag.
4. This is essentially what I do — leave pictures sitting on the floor. Sitting a piece of art on top of a stack of books (or is that a stack of decorative boxes?) makes it look less than accidental. Also in this photo: lean a piece of art on a bench or hall table for a more casual look. From Desire to Inspire.
5. You've seen gallery walls before… but I love how these art pieces wrap the couch and go all the way to the floor. From Desire to Inspire.
6. Lean smaller pieces behind the books on a bookshelf. Photo from Lonny.
7. Hang art in front of a vintage textile for a lovely, layered look. From Design*Sponge.
8. Just sitting a frame a chair works (but only if it's a chair you don't use much). From Elle Decor.
9. Frame a large piece of paper and then hang art in front of it (or affix picture molding to the wall and then paint the interior) for this frame-within-a-frame look. From Lonny.
10. How about… not hanging pictures at all? What makes this work, and not look completely haphazard, is the picture ledge above; in this case, the second 'ledge' is the floor. Skona Hem via From the Right Bank.
(Images: as credited above)