This is a common question. I admit that, when writing my book, I didn't really think about describing how to come into the poses. It just didn't occur to me. Generally, since we can take our time in Yin Yoga, the exact way to get into a posture didn't seem so important. But many people have wondered if there are better or worse ways to get into them. I will think about adding that in my "next edition"
In the meantime, I can think of 3 sources for folks who do want some advice on how to come into the poses.
1) Check out this article by Paul Grilley:
http://www.yogajournal.com/practice/579
2) Check out Biff's book The Yin Yoga Kit
3) Share your own ideas here on the forum! Maybe together, over time, we can create our own fun and creative ways into (and out of) the poses.
In the meantime, if you have a question about a particular pose, I would be happy to talk you through/in/out of it.
Cheers
Bernie