I have a giant Doubt Monster lurking behind me when it comes to the quality of my writing. (I would really appreciate it if two extremely hot brothers who deal with the Supernatural regularly would get on with killing it. I mean, it might as well be a demon.)
When it comes to other books, the Doubt Monster and I curl up on the couch together. I can only suspend my disbelief so far.
Here's some general rules to slay my Doubt Monster when I read your book. (This message is to unpublished and published writers alike. Also, while I say my, I'm positive this can be generalized to encompass most readers.)
1. If two characters are going to be madly in love, I need a bigger reason then she/he's hot. That isn't love, it's lust. And, I'm sorry, but lust isn't worth much more than a quick wham, bam, thank you ma'am!
2. If your character is going to go into a dangerous situation, they need a really good reason. Humans have something called a sense of self-preservation and if they're going to ignore their instincts, I want a why.
3. If there are paranormal or fantasy elements or you're creating a new world (dystopian, fantasy, sci-fi, even a tiny town) then you need a solid and logical foundation. Without a basic set of rules and standards, you have nothing to offer me but chaos and a world that makes no sense.
4. Never use characters for plot purposes alone. I don't care if you need Minor Character X in a bar to let slip Important Fact Y to your MC. If Minor Character X is only there to tell MC something, I will notice. And I will not be happy. Just like Main Characters, Minor Characters need to have their own purposes, motivations and goals - it doesn't matter if the reader knows them but it sure as heck matters if you do.
5. A plot twist is only a plot twist if it happens right in front of me. Meaning, that, once the twist is revealed, I should be able to look back at your story and see there was hints the whole time, they were just so subtle and well done that I didn't pick up on it. Blatant lying to create a plot twist isn't a good illusion, it's a cheap parlor trick and breaks the author/reader trust.
How do you feel when you encounter things on this list? Do you have anything to add?