I have read a lot of book about Rumi. This book makes some valuable additions to the literature about him. While we cannot absolutely know what transpired between Rumi and Shams, it is reasonable to imagine what the practice might have been, extrapolating from Rumi's writings. While the book's title say it addresses spiritual practices, it is fair to say that at least 90% of the book addresses only one practice: looking long and deeply into the eyes of a spiritual friend. Even if one does not have a spiritual friend to engage in this practice with, the author suggests you can use your own image in the mirror, or look long and lovingly at something in nature, like a tree.
The section of the book on stages of spiritual practice is useful. Also very useful and kindly written are the sections that address our tendency toward self castigation on the path: we are not enlightened enough, far enough along the path, find ourselves unworthy- etc. The author's heartfelt words about this reach right into the heart and comfort the weary traveler. The following Rumi poem, which I had not read before, is quoted:
You suppose that you're the trouble,
But you're really the cure.
You suppose that you're the lock in the door
But you're really the key that opens it.
It's too bad you want to be someone else.
You don't see your own face, your own beauty.
Yet, no one's face is more beautiful than yours.
I would like to hand that poem to every counseling client I see.
The chapter on sexuality, advising sacred friends who have sex with each other- on how to have sex with each other- seemed a bit out of place to me.
Overall I recommend this book highly. You can feel the author' compassionate spirit through his writing. Reading this book is like spending hours with a compassionate spiritual friend.