So many books, so little time. If you have trouble finishing books you've started or you just want to get through books faster , consider this "layered reading" technique.
The method comes from Design for Hackers author David Kadavy, who calls himself a scatterbrained person with no respect for authority. As such, the method recommends reading the book not in the cover-to-cover sequential order it's written in, but rather by jumping around to the parts that pique your curiosity. This system is for non-fiction paper books.
In the layered approach, you first read the table of contents and, for every chapter title, think about the "argument" of the book and questions you might have for each chapter. In the next few layers, you start with the chapters that aroused your curiosity most and, again, consider the questions they bring up, later jumping to other chapters to fill in any knowledge gaps.
This is a more thoughtful approach to reading non-fiction, and while you won't get the same experience or get all the content if you don't read the book cover to cover, it's a quick way to get a general understanding of the book in one sitting. Kadavy says:
Following where your curiosity leads you is the whole point of this methodology. Instead of wasting weeks and months on books that bore you, you'll find and "read" books that do interest you in a fraction of the time.