My worst (and sad to say often reoccurring) boo-boo, is when making the binding. I get all the strips I need all lined up and if the fabric is a little hard to tell which is right or wrong side, I'll sew them different ways. One night, I took them apart 3 times and when they STILL weren't right, I threw them on the floor, stomped on them good and proper and left the room :oops: :oops: :oops: :roll: