Here's a few tips. 

- if your  book has a lot of emotion in it. Not a lot of people will read it. 
     
"Don't you ever do that again! " Thomas said, when I came back from jumping in the deep side of the pool. " you scared me to death, I thought you was gonna die." He started to cry. " I'm sorry, I really am. " I started to cry. 

-  don't have horrible grammar/can't spell. 

" so like she said I am a bish and I was like bish no I cans beat u into like next week so like stfu u ugly duck " 

- use """ when someone is speaking. 
Not-

You're my new child Amber he said. Oh my god thank you so much i said. Then we all started talking in our minds like we're telepathic. 

- don't have the main character fall for the other main, in a snap. 

 As I was walking into the dollar store to get some candy, I bumped into the cute guy. As soon as we locked eyes we started making out. He then took me home and we had three kids. 

- if it's a fan fiction ( the maze runner, the walking dead, one directions, ext. ) don't have the main forget who they are. 

I was walking to my friends house when suddenly a boy with long brown hair and blue eyes bumped into me. He looked very familiar but I couldn't remember where I seen him before. " sorry, my name is chandler Riggs aka Carl grimes on the walking dead. Gotta blast Brianna is about to kill me for signing a girls poster!" ( it's not like the main has 200 posters of chandler on her wall and watches the walking dead every night ) once the boy left I still couldn't figure out who he was.