Use Roller Shades
Roller Shades are a type of cheap blinds that look great while not costing you a fortune. Roller shades are made of a simple vinyl material that rolls up and down on a top-mounted roller. Simply pull the shade down to cover the window and give it a quick tug when it's pulled down to roll it back on itself.
One of the nicest things about roller shades is that they lack perforations: the whole-doth material blocks out a higher level of light. They can also be decorated in a variety of ways, depending on their location. A simple paint job can help them match any room.
For a kid's room, fun stickers can be plastered on the material that gives them the chance to personalize their own unique style. They can even be colored on with erasable markers.