Let them CREATE!
I knew something must have been up. Riley, my 14 year old was asking if we had any Christmas lights that she could have. I directed her to the attic and didn't ask any questions.
A few hours later I came into her room and saw lights hanging from her ceiling directly over her bed. What does a mom do? Freak out? Or embrace the creativity? Riley has always been interest in making her room a pleasant "cool" hang out for herself and her friends.
Growing up my parents never hindered my creativity. They weren't concerned if I hung posters all over my room, spray painted old things to make new or cut up old sheets to make new pillows. They really didn't even seem to notice!
In the town that I grew up in was a old fabric remnant store. You could get a yard of fabric for $1! Y'all that was paradise. As a child I didn't want to go to the toy store or even the candy aisle- just take me to the fabric remnant store!!! It was heaven! I remembered my grandmother taking me here quite often and i would buy me a new piece of fabric to cover my bulletin board. Just that little change would brighten my room and brighten my personality. My parents nor my grandmother every asked why or even try to direct my fabric choice to something a little less wacky....they just let me be Lisa.
Let your kids create! Let them make their space "their" space. Who knows what their little creative minds will come up with! Don't worry about the extra holes in the walls or the wacky color themed that is covering their four walls.
You can always just close their door.