I'm a measure twice, cut once, leave a witness kind of woodworker. I don't recall the last time I measured and cut something wrong(knock on wood). However, I make up for it with other types of 'oopses'... the last one resulted in dropping all lams and riser of a longbow, slathered up with glue, onto the floor and into a bunch of osage and yew shavings... like it was tarred and feathered... broke the fadeouts on both ends of the riser and had to make another one immediately... I had epoxy from my armpits to my knees because I tried, ungracefully and unsuccessfully, to catch everything :(