I don't know about dorm rooms these days, but the plastic beige blinds in my freshman dorm room made me feel like I was living in a mental institution. Not cool. You'd be amazed at how some cute, brightly patterned curtains can instantly inject some personality into your space and make it feel homey.
You can buy ready-to-hang curtains like these cute zig-zag print ones, or hit up the fabric store for a few yards of pretty cotton and convince a fashion design major friend to hem them for you in exchange for cookies or math notes.
[Zig Zag Curtains: $59, Wayfair]