There’s no method to increase your chances in these schools. If there were, everyone would be doing it, nullifying your chances anyway. All the competitive applicants have a perfect/near perfect GPA. They all have near perfect SAT scores. All of them have an essay, and all of them think their essay is going to get them in. 5% of them get in. It’s more a lottery than a competition. There’s no reason to start spending $$ for things like that.