Pam like most things in life there is no 'right' or 'wrong' way, there is the way that works best for you. The technique for using the rulers and rotary cutters have been established for what will 'generally' give you the most accurate and consistent cuts while being safe, but it is not a rule. From my experience in teaching I have found that mostly people have gone out and bought their tools without anyone ever actually showing them the best or safe way to use them. BUT, don't assume that there is only one way, I have learnt a lot from students who were not showed how something 'should' be done. There are videos available on the internet that show several ways of cutting, try some of them and pick what works for you.