Easy just add a radio, a little bed side table, a nice bed spread and of coarse a dresser. You could also have a thing to put your shoes on. The most important thing is to have your room clean!
Lots of color variations and posters on the walls.
Make everything pink.
What will look amazing to you may not look so good to others. As it is your room and you will be living in it, just decorate it the way you like it.
Visible clutter is the worst. Make sure the room looks like there isn't anything in it but that its secretly stored away somewhere.
Usually when you paint a color a darker color (like red) it does make a room look a little smaller. In contrast, when you paint a room a lighter/pastel color it tends to make the room feel like its bigger.
her room is big , pink and it look nice ..
Make sure he is older than you take money and put it in his room and make it look like he stole it from your parent's or you
Make another room and take out the wall
Darker tints will make a room smaller.
Verticly striped curtains will make a small room look bigger.
First make a house. Then make a tunnel that leads to a secret room. You can hide the tunnel entrance by covering stuff over it so that it doesn't look suspicious, like a bookshelf.
By cleaning it
It can do but it is all in the mind as you know. The same applies to wallpaper. you hang wallpaper with narrow stripes it will make the room look smaller. hang w/ paper with wide stripes it will make the room look larger.