dont give up. do a few blocks simple like contrary wife or maybe the monkey wrench? go to quilters cache. also when your sewing put your ruler under the needle slowly putyour needle down are you truly sewing 12.5 inchs? also go for only three row quilt blocks til you get it down. each row the squares are 4.5 inches before you sew them to the next one three in a row.. so as you sew a to b measure did it come out 8.5 inches when sewn? if its a bit larger trim it down or check that seam. you should get 12.5 if not say help! skip points stars that stuff til you get the 12.5 down. use your ugliest fabrics to play with it. you can ONLY get better girl. dont ever give up. just keep trying honest it works everyone here can tell you that I surely know this .. oodles of trial and errors.