When first quilting the lady at the LQS told me that the rotary cutter blad was "Go to the hospital sharp" I try to make sure that the guard is on when I set it down. Also, I bend back my index finger a bit and check placement before i start cutting. I have nicked the ruler a few times. And oh yes, I have sewn thru my finger at least twice with the sewing machine needle. And just recently I was using the walking foot and got my thumb too close and slice off part of tip of my thumb. Now that hurt. Don't think I have ever moved so fast. Scared my cat and dog too.