Stitchomancy may sound like a term for divination involving sewing or knitting, some sort of craft that uses stitches. Don't let it fool you, stitchomancy is entirely different. Stitchomancy is also known a bibliomancy. (The term bibliomancy is used to specify stitchomancy that is performed using a copy of the Christian holy book, the Bible.) The practice of stitchomancy has been in use for a very long time.
There are signs indicating that it was used at least as early as the rise of Gnostic Christianity. A book from that period was found in Egypt called the Lots of Mary. The practice of casting lots was used in correlation with this text to divine answers to questions and seek out guidance upon life matters. While it may not be stitchomancy in the sense that most would consider it, it is still divination performed using a text. (The same argument can be made for using the I Ching for divination.)
Most of the time, stichomancy is performed with the querent holding a book within their hands. They ask the question they seek an answer to. Then, the book is opened to a random page. The first passage that their eye falls upon is the answer to their query. Some people use just one passage for the answer to their query. Others would repeat the process for additional clarification of the answer provided.
I personally find it helpful to have a wide array of books to choose from. This allows for a greater randomization of possible answers. Thus, I will select a random book from my personal library and then proceed through the process I described above. Generally, the interpretation of the results of stitchomancy varies as widely as the possible answers. The use of a text that is oriented towards divination practices (such as the I Ching) makes this process a bit easier.
At the same time, with some careful consideration, it is possible to discern how a passage relates to what was asked. Unlike other methods, there is a fairly high probability of getting a 'null' result. That is, a passage may be completely unrelated to the query made. In my practice, if I have three obviously unrelated responses to my query, I put the book aside and treat it as a non-answer.Thus, I will either choose a different divination method to seek out the answer to my query or I will end my divination session.
Some texts lend themselves towards easier divination practice. The Christian Bible is popular because there is a wide range of results that can be found that can make greater sense given most life situations than a books such as Bram Stoker's Dracula. (Though, I did have success using that text at one point. It was a very weird result that didn't fully make sens until well after the fact.) Other texts are not as friendly towards the practices, such as a chemistry text book. (I did this at one point and had a passage regarding Avagadro's Number come up as my result. It was very difficult to see how that related to the query.)
I prefer to use books of poetry for stitchomancy. I know one person that used song books for the practice. Any text that is used, the querent must rely upon their intuition and their ability to see a link between the result and their query. Of the different divination practices that can be used, stitchomancy is probably the easiest to practice discreetly in a public location. Because, the query needs not be voiced out loud. The passage can be randomly selected with the query firmly in the querent's mind. The result is the same as what there would have been if it was voiced out loud.