What are some do's and don'ts for the admissions essay?
Here are two easily avoidable DON'TS, both of which involve the crafting of your academic “persona,” or the aspects of character that you try to provide for an admissions counselor.
First, AVOID answering questions that portray you as a baby, a child, or otherwise immature. Answers that begin with phrases like “ever since I was three years old,” or “I can remember dressing up as a fireman when I was five,” or “for me, the first day of kindergarten was the scariest day ever.” It is overly sentimental, in the first place, and probably a bit of an application cliché (even though these memories are for you rather dear, remember that counselors probably read similar scenes all day!). You want to portray yourself a promising young adult, about to start making the first steps toward independence and adulthood; this involves creating a persona for yourself wherein you are disciplined, eager for challenges, proven in your abilities, etc. When you create a scenario wherein you are perceived as a child who is “playing” at being in the world (and probably still in diapers), you risk creating the exact opposite impression: immaturity, unpreparedness, and emotional instability.
Second, be careful not to swing in the other direction and become overly grandiose. AVOID vague, overly ambitious and naive descriptions of your goals or your accomplishments. For example, don’t create a persona wherein you are trying to save the world (e.g. “I want to cure cancer and find a solution to our energy crisis”) or wherein your minor extracurriculars are overly-inflated (“my one semester as vice secretary for the Student World Affairs Club changed my life” or “the two hours I volunteered at the soup kitchen really changed lives”). Be specific and be realistic: don’t say “I want to work with children,” if you can say “I hope to increase my volunteer efforts with after school programs and lobby for more funding for Teach for America.” Qualify your accomplishments into realizable chunks: “I am new to the Student World Affairs Club, but I hope to make its newsletters more effective.”
Rather than make these two common application mistakes, instead prefer specificity to vagueness, and a realistic portrayal of your current place in life: as a capable but eager-to-learn young adult getting ready to move into the world. You are neither a grandiose giant nor a silly baby, so don't portray yourself as one!