Start by cutting some pieces of foam as large as you would like your pad. Some shooters prefer a narrow stack of pads right at the top of the stock, other prefer to wrap larger pieces of foam over the full comb. It's up to you. You'll see as you wrap the foam with the tape that you'll be able to shape it a little by tightening or slacking your wrap a little.
Get some scotch tape and affix the foam to your stock and shoulder the rifle from a variety of positions, making sure it's comfortable and tall enough and there's no scope shadow in your view. I had to stack two pieces of foam to get to the right height.
I left the scotch tape on to hold the pads in place as I started to wrap them with the vet tape from one end. I removed the scotch tape once there was enough vet tape to hold everything in place. As you do this, you'll notice the texture of the sleeping pad will grip the stock and to the other piece of pad very well once under tension.
As you get to the ends, make sure the foam is completely covered with the Vetrap before finishing it on the bottom of the stock.
I added a piece of self-adhesive Velcro to the outside of the wrap so I could slap on a shell carrier that I had laying around if I want.