Four tips on making a creepypasta.

Work on your writing more

Make drafts, like write the story and then tweak it some more

make sure it makes sense. like for an example, (i.e Jef the killer was burnt, and he still had hair and his skin was white and not burnt, makes no sense) even if it's not real, still should make some sort of sense,

And lastly, make sure it's not a copycat of any other pasta,

And check your grammar and make sure you use enough periods, but not too many