Once had the bright idea of sewing rag quilt blocks together with my zipper foot because I could get SOOOO close to the batting ... well there was also no protection with the needle to the right of the foot and sewed through my finger!!
Was taking a class a convention once when we were trying to hurry through something because we were running out of time. Somehow instead of sewing one handle on one piece and another on the other piece I sewed the handle front to back. Looked sort of like suspenders! Needless to say, I never finished that bag!