Fiona Duthie has posted a free tutorial on her blog which looks fabulous. It reminds me of some of Ruth's posts because she uses layout to achieve differential shrinkage and thus shaping. I think I will have to try and make one.
I had a go at this and thought that you might like to see the result. Although I'm not usually a poncho wearer, I'm really pleased with it and plan to make another at some point. It wasn't very difficult, the main problems I had were not having a big enough table to do the layout on and finding enough time to do it.