I made one of these curtains for my secret den because I am poor and cannot afford to buy curtains, although not rich in currency I am rich in junk and creativity ;) additionally these curtains are great for places where you can't put up a proper curtain rail.
You will need:
Fabric (the size of the hole you intend to cover or bigger)
Screws ( x2 )
Optional but usefull extras:
Eyelets and eyelet pliers
Swiss army knife and/or other cutting impliments
Step 1: Make holes in fabric
I advise you make the holes about 10cm / 4inches apart, but you can make as many or as few as you want.
Step 2: Optional: add eyelets
(For those who don't know what eyelets are)
Step 3: String
To make it, cut some string to a length that is longer than the curtain and tie a loop in one end of the string. You can tie it any way you please but I find that the most sturdy way is to fold the string over so it is doubled up, then tie that in a knot leaving a small loop (pictured below)