Past Lives and Tarot

I've been becoming increasingly interested in doing more past life readings. But, as I've learned, they can be very difficult to do sometimes. So I was wondering if anyone has any helpful tips in interpreting the cards in relation to a past life.

I bought a book based on readings about past life. But I haven't been able to try any of the spreads. The book is called "Past-Life & Karmic Tarot" which is published by Llewellyn. I got it for half price on ebay which they are still selling.