Getting relaxed and saying affirmations just before you begin writing, studying, playing music, running onto the field with the team, making telephone calls for telemarketing, important meetings and interviews can be done just moments before the event. It's like getting into the Accelerated Learning State just before PhotoReading itself.
You don't need to incubate that. What you are incubating is the "data sorting" by the inner mind.
You might want to look at something like The Silva Method, dynamic meditation techniques or Silva Ultramind. Yeah I'm a Silva Ultramind Instructor. The Silva Method is the competition so this isn't a shameless plug. Just a suggestion there are already these techniques out there.
That's why it isn't in the book. It would just become more confusing since the book is aimed at teaching the PhotoReading skill.
Alex