We all know by now that the second most common piece of writing advice is to read more and read widely (the first being to just write).
Reading current books lets you know what's happening in the market. Reading classics lets you know what has stood the test of time. Reading within your genre teaches you the rules and the expectations of your readers. Reading outside of your genre shows you how to break those tropes.
I often think that the majority of the questions on this sub ("How do I do X?" and "Can I do Y?") can be answered with a book recommendation. Here is a book where that thing was done well. Read it and learn.
I would love for people to recommend books that are excellent examples of how to do something. Share a book that has particularly good characterization or pacing. What book has a twist that was done very well? Which book has a great unreliable narrator? What book does flashbacks well? What's a book told from the point of view of a child or an animal? What book makes great use of texting or email?
Feel free to request recommendations on specific topics as well!
Source: reddit post