I am guilty of all of the above but the one that irritates me the most and I don't know what to do about it is when I nick the edge of my ruler with my rotary cutter. I do this quite often and do not for the life of me know how I do it, I try to be so careful when I put my blade down but it happens all to frequently. I would definitely appreciate any suggestions as to how to break this bad habit, I go thru so many blades very quickly by doing this.