From 1999 - 2005 I made a small quilt a week, some of which are in my book The Uncommon Quilter. I took 2006 off because I needed a break, and I decided to create one 12 x 12 x 12 piece each month in 2007.
You can see all twelve of my 2007 12 x 12 x 12 pieces on my website, and you can read about my process for most of them on my blog.
The 12" x 12" size, and the monthly timeframe, has been a good set up for me. I plan on continuing the same series in 2008.