Though I have read through them, I have not actually done the exercises in practice. Given my unfortunate "closed-head" status, it will likely take me months to work up to any decent level of skill in this area. But I do think this is the book that will help me finally break through my own mental barriers.
There are several descriptive passages included, to help you visualize your journeys. As you get better at it, you should rely more on your own imagination to explore the inner worlds.
As she states at the beginning, the exercises were originally designed to be used when working in a group. While they have all been re-written for individuals, there are many times through the text where she talks about being in a group, and how to get assistance from others in your group. If I had a group to work with, I likely wouldn't be trying to learn these skills from a book.
Though by offering up examples and suggestions from all the people she has worked with, you can get a mix of approaches and ideas that worked for different people.
http://pythorium.com/bookreviews/tranceportation