So many writers are looking at Jeff the Killer, Slenderman, Sonic.exe and "scary popup" pastas. It's sickening what you call good. So, we came up with a list of what not to do. But that'd be boring, so let's make a story. Remember, I'm too lazy to make a list, so we made the story. See if you can find all the no-no's in this story.
"OH GOD, GUYS, you are never gonna believe this, like, 666, 13 and 43 are my fav numbers, but, that's besides the point, My little brother, he just like, fucking FLIPPED, AND STABBED OUR DAD TO DEATH, LIKE, WTF MAN, But no, that's not all, we recorded our bedrooms, and I caught my bro doin' the frickle frackle with his blow u- I mean, a weird creature came into his room, and stuffed his foot in his mouth, choking him to death. We don't know what happened, the tape was lost and we all died in the end. Oh hey, you look familiar, are you my brother?"
See? It's terrible. NEVER do this. Shock endings are great when pulled off correctly, but you may not understand what you need to do for it. If you don't understand it, ask for help instead of bitching at the people who take time out of their day to help this site. The JtK theory, where a family member goes cray-cray and then homocidal is a no-no. So are using caps excessively. And having tapes that are "mysteriously disappearing" are quite annoying.
Just a lil' tip from me to you.