Pay attention, kids; this is some excellent advice.
“My best advice is don’t write a boring essay. Sometimes I just read a first sentence like, ‘This one time I changed the world with my church group by playing the tambourine in Costa Rica…’ and I put that file directly into the ‘to be considered much later’ back-burner pile. Tell me who you actually are, and it is such a welcome change.”— Midwestern public university admission officer
“I wish students understood what really makes a competitive application for the most selective colleges. I've seen time and again students with excellent standardized test scores and mediocre grades expect to have a reasonable chance of admission. The reality is, if s/he has no ‘hook’—for example, not a legacy, not underrepresented (with respect to ethnicity or geography), and not a recruited athlete—then the most selective colleges will reject the application. There are far too many applicants with excellent grades and excellent test scores— not to mention letters of recommendation, activities, and essays—to justify admitting a student with mediocre grades. Highly selective colleges will likely perceive these types of applicants as lazy: obviously very bright students who were not motivated to work hard in high school.”— Former Ivy League admission officer and current East Coast private college consultant
“In my book, the biggest mistake an applicant makes is when they answer the [essay] prompt from another school. It’s so apparent they’ve just cut and pasted from that school’s application. Why bother applying if you’re not going to edit the essay for our application?”— East Coast liberal arts college admissions dean
Also see "Praising the low grade for a harder course".