For a kids room. Center a rod attached to the ceiling and aligned with the middle of the mattress. Hang and drape a measurably long length of fabric into a canopy. It gives a tent effect. Kids love that. Plus, you can add and remove on a whim.
For a modern take on a traditional canopy bed, try bed curtains. Instead of being mounted on a canopy bed, these curtains look great hung from the ceiling. You can use a combination of standard curtain rods mounted on the ceiling to create this look.