Curtains

hmmm well you wont need to put a fully installed curtain but you know the wire thingy you put netting on? should be readily available. on each side of door frame just put in little hooks. hook this up with your curtain on...for the curtain if youre doing it yourself youll just need to flip the top and sew so theres like a hole going all the way through which youd put the wire through.
Hope that makes sense

I wanted something a bit more professional and formal looking though. :X Though, I guess I'll have to use that if worst comes to worst.

take an iron rod, weld it at the top of your window or door, take a curtain, attach hooks to it and hang it over the rod, easy peasy.