I'm going to show you how to cut hair in layers.
Layering, first of all, is a removal of weight. Basically what you're going to do, Chris' hair is quite short on the sides but I can show you on the top how that's going to work. Again, you literally lift the hair out from exactly the place that it grows, i.e. just 90 degrees from the head, and cut the weight out that way.
No overt direction in any way. Not forward or backward, simply cut straight up at 90 degrees from the head. If the sides of Chris' hair were longer I would come around here, I would do the exact same thing through the sides. I'm going to show you this corner here. That is layering hair. So you've gone 90 degrees, 90 degrees from here. A complete removal of weight.