You might be focusing too much on trying to get to the desired state and interferring with your ability to relax enough to get there. After you've been in state a few times, you should be familiar with the physical and mental feelings associated with it. Try to close your eyes, relax, and as you breath out imagine those feelings. Don't try to force the sensations - rather, let them flow over you. Play around with getting into state a few times this way and see how your PhotoReading goes.
The very deep states, associated with very low alpha and mid-high theta, you probably won't maintain too well while PhotoReading anyways - the chanting and page turning will help you stay in mid-range alpha, but the eyes open theta state is probably not happening. The idea is not to become catatonic while PhotoReading, but to quiet the conscious mind enough to allow the preconscious processor to work at maximum efficiency. Remember - relax and play with the system. If something seems to work, do more of it. If it doesn't, do less. What gets me into state won't necessarily be the same thing that gets you into state.
