Here are some of my personal reading pet peeves. Remember, these are just my own, and yours will probably be different. Your audience will *probably* have similar pet peeves, so pay attention to what bothers you personally. It's okay if our lists aren't the same.
Here we go...
When everyone won’t stop talking about how amazing the hero is, whether or not she’s already proven herself. For example, Candy in the Abarat books. I loved these books up until “Absolute Midnight,” which I still don’t know what to make of. It’s not that I didn’t like it, it’s just that it… confused me. Plus, all the characters shower Candy with nonstop praise, reaffirming their loyalty at every chance they get. Now, she has already done a lot for them, as this is a later book in the series. But it gets old quickly, plus it just isn’t real. It’s natural for people to have doubts, even about someone they love and want to believe in. Constant praise of the main character means losing potential for conflict. Also, it’s straight up annoying.
How to fix it: Cut all the empty dialogue that’s just empty praise. Have a few characters who doubt your main hero, who drive him/her to prove them wrong.
On a similar note, the main characters significant other constantly telling us, “God, I love him/her so much,” while watching them. This gets old so fast.
How to fix it: Things like a brief touch, locking eyes, or small smiles are much better at conveying love. Show don’t tell. Also, it's perfectly realistic for even the love of one's life to have moments of doubt. It's human. Readers like human characters.
Ancient supernatural beings who act like whiney teenagers. You know what I mean, characters with eternal youth, like Edward from Twilight who are supposed to be thousands (or whatever) of years old, but act like the age they look instead of the age they are. Eternal youth is not supposed to mean their brain stopped growing. If I’m going to believe your old, act old. Don’t throw a fit over your crush doing something that might mean something that bothers you.
How to fix it: Think about what time period your character is from, and what was normal back then. Perhaps he’s acting like an old-fashioned gentleman when he looks like a sixteen-year-old high school student, and all his friends are the not-so-nice stereotype of boys his age. This is actually a fun character quirk, so don’t lose it.
When a villain kills one of his people, or people on the same side spend too much time fighting with each other. It’s just an easy way out to have the villain destroy himself. And if people on the “good side” have some sort of ritual to test the main character’s strength, make sure there’s a good reason behind it, because it can really slow down the story.
How to fix it: I've always found romances between two villains, or family relationships between villains, to be completely adorable. Let them be evil together, and loyal to each other. It makes readers kind of like them, which adds depth to your story.
That's all for now, but I've got tons of these, and I keep acquiring more. There will definitely be more posted in the future.
Again, these are only my personal reading pet peeves, and just because you have one of these in your book doesn’t mean it’s ruined or that you need to get rid of it. Do consider that it might be annoying, though. But my point is, it’s important for you to identify your own so you’ll know what not to do. Your audience is likely to be people like you, so they’re likely to have the same pet peeves.