When I decided to paint more than one shoe the 8" square seemed to work best. Painting looser is something I have been trying to do. Losing edges is a goal also. After taking this long break from painting my perspective seems different also.
My blog: http://claudiahammer.blogspot.com
My website: http://claudiahammer.com
My email: firstname.lastname@example.org
My DPW gallery: http://www.dailypaintworks.com/Artists/chammer-209