Hey rawrrawr,
Well first of all, I don't think it's possible to be doing it wrong. Your eyes are constantly taking in all the information that is given to them and most all of it is perceived at a non conscious level.
With that said, the only way to do it right, is to KNOW you're doing it right.
With your first few books, it won't work as well as you hope. That's a given, and it happens to everyone. Keep photoreading and it will begin working for you after your first few books. Photoread everything you can get your hands on, activate everything you need, but most importantly stay with it.
Go through the photoreading book again and see any points you might have missed before.
Also,
While photoreading, you don't scan the page. You look at the center of the book, and try to imagine an X going through the center and touching all the corners. This is just so that you can see all the four corners and the center of the book, to make sure your mind is absorbing everything on the page.
Good luck and continue photoreading.
-JackTuff13