I'll chalk this week's effort up as research and practice.
Swatches 17 - 20 are all about buttonholes so I dug out all my reference books and found every mention of every type of buttonhole I could. The little strip on top was a bit of practice. In the end I decided that I will wait for the April issue of "Cast On", the TKGA magazine, which is supposed to be coming out with an entire article on buttonholes. Other technical articles I have found in the magazine have always been quite enlightening, often refining techniques in a way I have not found in my other references.
Maybe I'll start on the argyle sock or vest. I have the yarn for both.