Extreme sports have grown in popularity among tween boys in recent years. Surfing and skateboarding, in particular, have gained legions of tween followers. If you don't live surfside, you can easily bring the beach to the bedroom. Paint the walls a calming ocean blue and add a wall decal of a surfer or surfboard. Skateboarding fans might like to mount their old boards on the wall for a cool accent. Large posters of skating and surfing scenes can be framed and hung as well. Swimwear and skating brands also sell themed bedding to tie the room together.
For a laid-back touch, paint a wall with writable chalkboard paint so your tween son can jot down test and homework reminders to make sure he has enough time to hang 10 in the sun.