I found that many books start with "The" and that gets in the way of a good poem. Finding a book that starts with a preposition or gerund is golden. And it works better if you ignore the subtitles.
You can "write" as many lines as you wish, but I like the sound of a four-line poem.
Here is my first attempt at Book Spine Poetry. I'll post the photo first, followed by the poem typed out.
Two old women
Living on the edge
In the land of white death.
Snowstruck.
The everlasting man
Walking on water,
Swimming with giants,
In search of birds and wild places.
To be a slave,
Hostage to the devil,
The worst hard time,
No end in sight.
The Orthodox way,
The way of a pilgrim,
Path to sanity,
A tiny step away from deepest faith.