I used to write a lot of dream sequences and I used to really enjoy writing them and reading them in other books. But now, when I read a dream sequence, I kind of roll my eyes because I don’t really see them as necessary anymore. I feel like there are a lot of other ways to foreshadow or convey emotion or give insight into the state of a character’s subconscious than relying on dream sequences.
Of course, it’s an entirely different matter when dreams and dreaming are the main theme of the book. Most of the time, I still feel like dream sequences are almost an easy way out and an excuse to fit fantastical elements into the story. In other words, I think dream sequences are a lot more fun for the author to write than they are for the reader to read. I suppose they seem a little indulgent to me.
However, dream sequences are a great tactic to use in NaNoWriMo, when the point is to get a great word count and worry about revision and the rules of writing later. They can also help you get to know your characters better in early drafts. They’re also good in small doses to add humor. But when it comes time to really get to work on revising your story and making it better, I wouldn’t rely on too many dream sequences, unless that’s the whole premise of your book.