As a freshman at Marist College, I live in Marian Hall which is the best dorm for a fashionista like myself and my roommates--we have a walk-in closet! This huge closet is amazing but a little drab so we decided to hang a curtain over the closet entrance to brighten up the space as well as offer some privacy as a changing area.
After a little research, I discovered that this is quite possibly the simplest DIY ever.
You only need two things: a tension rod and a fabric curtain. I bought both from Target, the (28-48") spring tension rod for $5 and the Xhilaration (84") Window Panel for $20.
Just a note: make sure the curtain rod you buy is a lightweight, spring tension rod. This means that it uses the tension of a spring against the wall to hold up the rod and you will not need any nails or glue to attach it to the wall.
To put up the curtain, first measure the rod against the door frame. Twist one end of the rod to make it longer or shorter until it is about one inch wider than the door frame. Test the position of the rod, optimal position is 2 - 3 inches below the top of the door frame
Now all you have to do is slide the rod through the top of the curtain and voila! You have a curtain to cover your closet, decorate your space & offer some privacy in your dorm room. You can also take it down at any time or switch out the curtain for a new pattern by simply retracting the rod to take it out of the door frame.