When I make log cabin blocks I cut as I go and make the
"the logs" about 1/8-1/4" wider & 1/2" longer than needed so that I can trim as I sew them, built in fudge factor.
My log cabin blocks are totally scrappy. You can look at a picture of one of them here:
http://good-times.webshots.com/photo...45965719chaqYB
Sharon W.