Yeah...I was going to say...there is the old sheet approch...*smiles*
But I totally understand about wanting a cool cloak. My friend LARPs. I myself have a cool cloak for when I throw Harry Potter themed capes....I have not yet found a better one...my mom made it for me and it is super heavy and I found a kick *** Hogwarts patch for it....very nice....
I am sorry...I don't know of any good patterns...*smiles*
Growing old is mandatory, growing UP is optional!