A simple, inexpensive canopy can be made with an embroidery hoop, sheer curtains or plain sheets, a ceiling screw hook and ribbon. Other options are using a dowel, curtain rods or even a towel rack.
Start with the inside circle of the embroidery hoop and tie ribbon in three equal segments. Thread the curtain to the outer circle. If using sheets, sew in a hem ahead of time. If desired, before assembly, decorate the sheet or curtains by gluing ribbon, pompoms or tassels to the outer edge. Assemble the two circles and tighten. Make sure the curtain is even around the outer circle. Tie the ribbons into a knot. Install the screw hook into the ceiling, and hang the canopy from the ribbons.
Alternatively, use a long dowel instead of an embroidery hook. Thread the curtain along a dowel as long as the bed is wide. Use thumb tacks to tack the curtains to the ceiling. Another option is using curtain rods. Install two straight curtain rods into the ceiling parallel to the length of the bed. Drape the fabric across the two rods, allowing excess fabric to cascade down the sides. To make a canopy that comes out of the wall, install a towel rack, threading it ahead of time with the desired fabric or attaching the fabric with shower curtain rings.