The grip on the razor is a funny thing. We all have our own way of doing it, although there are only so many ways you can do it so there are some similarities for sure. You will always be able to tell you are holding the razor correctly when it is comfortable and you have control. If you feel as though you are lacking control, then you should alway correct that. When I am doing a near sideway pass on my neck, my grip has the scales positioned at the first 90 degrees when opening the razor. I find them to be in my way if they are in the usual open position. It may seem odd but it gets them to where they are not banging against my neck or if straight down they touch my chest. I do not always hold the razor this way or that for an entire shave. There are often three positions for the scales for the most part. Often that is nearly straight down, but for thing like my mustache, I go with the commonly seen scales 90 degrees to the spine. My finger move around in my grip often. When my stroke changes something else like finger position changes too. If you are comfortable and in control, and getting good shaves you are doing it right. Do not be afraid to change things a little to find your perfect shave.