I found a collection of wonderful medieval, cloak and hood patterns and tutorials by the oh-so-talented-and-generous Eqos on deviantart. I love these patterns - they're very easy to follow and the construction is authentic, which I appreciate. She has Quiddich robes in several sizes as well!
If you're after a cloak or robe pattern and tutorials and you have basic understanding of sewing skills, hers are good, with minimum cloth wastage and good, clear tutorials.
I'll just post one scaled down example here and you can see her others at
http://eqos.deviantart.com/gallery/1866026/Patterns-Tutorials http://eqos.deviantart.com/art/Pattern-Sleeveless-Cloak-Duster-137941608 I couldn't resist - here's one more that would make a good Jedi, Sith or Emperor's Robe:
http://eqos.deviantart.com/art/Pattern-Large-Hooded-Cloak-160995777 If what you're after isn't there, there are quite a few people who generously post their patterns etc on deviantart so have a cruise around and you may just find what you're looking for - clever clogs, they are!
Hope you find these useful!
DL