If you want to see a nice looking, quick to tie pattern for a Green Caddis Larva, check this link to the tutorial on Loren Williams website (flyguysoutfitting.com). Simple but deadly, not to be confused with silent but deadly:
http://www.flyguysoutfitting.com/rhyacophilia.html
If you have any questions about the pattern (sizes, best time to fish, type of water it works best in, how to fish it/rig it, etc.), ask here and I'm sure Loren will be happy to answer them (I pimped ya out Loren!).