Pacing in a story is probably a factor we don't think about. But it is. With writing if too much action is packed into the beginning it gets all mangled up and people can't tell what is going on.

Also don't make up random dilemmas in the book out of nowhere and expect your story to be good. For instance, I was reading a fanfiction where the two characters were happy and together doing some playful banter then blam! The girl has a sword through her stomach with no hinting at a conflict or a possible death. It killed me on the inside to watch a good story go to waste because they lacked proper pacing.

At the beginning of a story leave out some of the action and slowly clue in the readers as you go along, giving bigger hints every so often, not chapter after chapter. This will allow a longer story and a more enjoyable read.

If there is a twist in the story hint at it at the end of the chapter a little bit to get readers interested in that new part of the story, they will probably remember that hint better because it's fresher in their mind. Let me give an example, if our main character is a target of stalking, murder, or kidnapping, have them bump into the culprit and think nothing of it and then have the man/woman think or mutter something to catch people's attention. This is dramatic irony, which is when readers know more than characters in a show/play/movie/book.

Also don't make the conflict disappear too quickly, at the climax make the finale stretch out for two or three chapters, like cliffhangers, to keep suspense.