How to cut hair with a razor: there are two ways, this is the first of two ways. I'm working on the perimeter, and I want to take this length from being a blunt and heavy line, to a much softer, more diffused, little more broken up, little more natural. How I do that; place your model's head down a little bit. Comb tension nice and tight. Using the center section of the blade, shave; it's almost like a shaving motion. What you're doing is taking the weight away, which is what you're doing when you use a razor, you take the weight away. But, I"m being very specific on where I'm doing it right now. You can see what I do, I just comb over the ends of the hair, so what you get is a much thinner, softer, more broken up, get away from the blunt line. That's how you cut the hair with a razor.