I've been having the most difficult time with most second books. I'm writing book two of The House of Slide, or I should say, I'm rewriting my rewrite's rewrite, because I've been reading second books in series that have problems I'm trying to avoid. This always surprises me (I don't know why because I realize it ALL the time), but it's harder to write a book than to read it which makes me as a reader overly critical of me as an author. The biggest problems that I've had, and that other books with second books that disappointing are;
Whining. Stuff sucks, and the character is overwhelmed, the author is overwhelmed, and so everything's bleak and there's whining. And more whining (I think authors are whiny as a group. I am demonstrating this trait with my current whining about whining:).
Second problem is having fixed points that the characters must navigate to achieve the ultimate goals at the end of the series without having schizophrenic characters in the duration. Very difficult to do when something must happen but how to make the characters do it naturally? First books do not suffer from this because the ending is open. Next book, less so. (I'm hoping third books are not as difficult because so many books have sluggish hard to read middle books that are simply lovely at the end. Hmm. I'm wondering if that has something to do with the growth the author has writing the tricky sequel. One way to find out)
Third thing is pacing. The book usually drags while the character whines and then the action is all crammed into the end. Love triangles make this much worse and more likely.
Cliffhangers are the inevitable result of a book where the author gave up trying to make anything rational and is relying on the last book to save her. Sigh. Knowing the problems should help one avoid them, right? Um, we'll see. Sigh. (Sighing is a clever disguise for whining:)