Discuss the design of the new room with your child. While you ultimately have final say over decisions made about the room, allowing your son or daughter to have input into the design can make the whole process a lot easier.
Purchase new furniture for the room. Buying a complete bedroom set allows you to get a bed, nightstands and a dresser that match, but you can also buy separate pieces that complement each other.
Decide how much storage space you need in the room. If closet space is limited, considering installing a storage system that allows you to hang clothes on two levels. Purchase a bed that has drawer storage underneath, which can be ideal for storing out-of-season clothes. If there is open space beneath the bed, plastic bins that fit underneath are a cheap way to utilize that space.
Paint the walls. Use a paint that is durable, since many teenagers hang posters and pictures on their walls.
Add a designated workstation to the room. This can involve purchasing a simple desk for your child to do homework on, or a computer table and a new computer.
Accessorize the room. This can be done in a myriad of ways, including hanging a bulletin board on the wall, placing a basketball hoop on the door and using items such as lights, trash cans or wall hangings that feature your child's favorite sports team or other interests he or she has.