If you're a handy type person who enjoys projects, then you don't necessarily have to run right out and buy a canopy consider making one. Making a kids canopy is relatively easy since it doesn't require sewing just a little organizing and planning a few items from your local fabric store.
Before you begin you want to get yourself a nice long measuring tape, a chandelier hook, a lightweight hoop, some twine, a hot glue gun. Of course you will also want to get material for hanging in the color or characters that you or your child desire. While choosing your material remember to buy enough that it will evenly cover the bed.
The first thing you need to do is make a mark on the ceiling, where you would like the canopy to hang measuring to decide the length you want your curtains to fall. It's a really good idea if possible for you to hang your canopy from the support beam to avoid plaster weakening from holding the weight. Next you will want to cut two pieces of twine, and knot them together at their center point of the kids canopy and then tie all four ends of the twine onto the hoop, leaving an even amount of space between each piece of twine.
After you have prepared your hoop thread your curtains through the hoop one curtain at a time and gather them as tightly as possible securing them by carefully tying off the pieces of twine. After you have tested your kids canopy to see if it will hold simply hang the hoop from the ceiling, allowing the curtains to fall gently onto the floor at either side of the bed.