There are at least two ways to read: the reader's way and the writer's way. The reader reads to get an emotional experience out of a story. The writer reads to dissect it. Being able to read both ways is essential because both ways teach you how to write better.
I can't provide many tips on how to read as a reader. All I'll say is that for me it's like turning off a switch. I have to be present to the book and not think about myself or my work. The learning that takes place from this way of reading occurs after the reading is done, when I can ask myself things like, Why did I enjoy the book? What did I enjoy about the book?
When reading as a writer, I've come up with a longer list of things I look for, techniques that I can use (or steal, if you'd rather). While the first way of reading addresses why and what, the second way of reading often addresses how.
1. Style-How do my favorite authors create a writing style that I enjoy? For me, I'm usually drawn to lyrical writing, writing that flows continuously. I try to look for how writers start and end sentences and paragraphs. I look for how they punctuate sentences and what kind of structures they use for these sentences. I look for the type of vocabulary they use, the sounds they use, the level of formality they use.
2. Structure-How do writers organize their stories? How do they introduce back story and conflict? Where and how to they reach climactic high points? How do they start and end stories?
3. Characters-How do great writers create characters that jump off the page? Critic Harold Bloom often uses a term that I connect with well. In talking about great characters, he often says that stories can't contain them. Why are people so drawn to Hamlet and Lady MacBeth? What makes Charles Dicken's characters so inspirational for people? Comparing characters and finding passages where a story can't contain the character usually reveals to me what makes them particularly vivid.
4. Subject matter-While I believe that any subject matter can be turned into a great story, critical reading helps me discover the types of subjects that are unusual versus ones that are more common. As an editor, I've really become conscious of themes that EVERY beginning writers seems to want to address: getting cancer, breaking up with a lover, childhood firsts. Stories about any of these subject matters have the potential to be great, but usually they have to overcome that initial feeling of, "Not another one of these." Paying attention to the subject matter of great writers usually makes you see other parts of the world besides those initial points of inspiration. It helps you see that subjects you might not thing of using can truly be developed into a moving story.
4. Transitions-How do writers move from one scene to the next? or one action to the next? What is the connective tissue they put in place so that a reader doesn't feel unintentionally jarred? If a writer is describing an action scene, how does he or she keep it from sounding like a laundry list? If a writer is shifting tenses or point of view, how do they do it successfully so that you're not distracted by the craft?
5. Dialog-How is dialog punctuated so that it feels like a character is talking naturally? What dialog is left out that makes it a distinct thing from real verbal interactions? How are characters differentiated through their dialog? How do writers use dialog to convey other information?
6. Descriptions-Different readers can tolerate different levels of description. How does your favorite writer create a time and place without annoying you?
7. Showing versus telling-All stories-at least all the ones I've encountered have some level of telling. How do writers decide when to tell and when to show? How and when do they show or tell effectively?
I'm sure that as soon as I publish this post, a dozen other items will occur to me. But, hopefully this list triggers some of your own technical difficulties that you can solve through critical reading as a writer. And, though this may seem obvious, I'll say it anyway, only because it's something I often forget: Your favorite writer hasn't necessarily mastered every aspect of writing. Use each writer for their strengths, and look to other writers to address things that you still can't figure out on your own.
Reading is essential to learning how to write, at least from my own personal experience. The more deeply you look at the work of someone you admire, the more you will learn from it. I often reread passages of Kitchen or Anna Karenina or Light In August. Often, just spending five minutes with a book I admire teaches me a dozen new things I hadn't noticed before.