There are several ways to suspend art to make a visual display along walls. You can spend a lot of money for elaborate hanging systems from art galleries and home-décor stores, but we're talking about ways to do things that give you unique art displays without breaking the bank.
One way to suspend art is to make the suspension part of the display rather than something that's hidden out of sight. You can secure various materials as a cable from hooks, nails or screws along a wall, or even from one wall to another across a corner. Find cable materials at hardware, home improvement, craft or even fabric stores: Clothesline, metal cable, knotted fabric strips – anything that hangs and can hold some weight works. Then suspend whatever you want to display by clips or clothespins. You can do this to make changing wall art out of children's handiwork, greeting cards, flowers or autumn leaves pressed between waxed paper, or anything that's decorative and relatively lightweight.
Decorative ribbons also work well. Attach several small, framed pictures to a wide ribbon, one above the other, and hang the ribbon. You could try hanging one picture per ribbon, using a ribbon that complements the picture inside the frame. Small framed photos of wildflowers, for example, could be hung on ribbons that pick up the flowers' main color.
If the object you want to suspend is the main focus of your display, you may want to direct attention away from the hanging apparatus. Monofilament, a single strand of some untwisted fiber such as nylon, often used for fishing line, becomes nearly invisible when hanging. It can be great for suspending "found" objects you want to use as wall art displays. You can use anything that catches your eye in a thrift store, junkyard or attic. Try an old window, a birdcage, a tobacco basket, a sign from a country store, a crosscut saw or other old tool. Florist's wire, available at floral shops and craft stores, also work well for this purpose.
You can even suspend an entire shelf and use that to display your art, but shelves are a topic in themselves. Keep reading.