The key is speed. Just zip through it as fast as you possibley can. Spend only like 30 seconds previewing. When previewing i usually enter the accel learning state then zip through the table of content.
As for affirmation i often use "as i photoread this book (titile) i am extremely curious to know how many way my unconcious mind is communicating to me " and "as i photoread my concentration is absolute" as well as "after i photoread this book i will be totally relaxed"
Just say those to yourself as affimation. As for purpose, I often found it better if i was more specific. Just "to deepen my knowledge" is a little vague for me.
Momentum is the key! Once you get going, you'll find it easier to keep going. Don't think about what you are doing; don't worry about wheather or not you are doing it right, just do it 
