Go in neutral with no expectations. Pretend you're going to sleep and the practitioner is reading you a bedtime story, use your imagination, and let your mind create the pictures. By doing this, your using the part of your brain (right side) where your subconscious or higher self will use to show you specific past lives images based on your intentions for the session. Limit caffeine before. Go with an open mind and trust yourself. I'm a BQH (Beyond Quantum Healing) practitioner which is the same idea but different technique. It also derives from QHHT. Hope this helps and good luck!
@Christine Nowinski Agree with Christine! the energy during these sessions can be intense that they drain the batteries quickly. Your practitioner should know this and always have extra batteries on hand. You can also bring your own recorder as a backup as well.