I majored in Philosophy at the University of Pennsylvania, my career path has included time on Wall Street and in product management and corporate consulting, and I love teaching/coaching. So what? So what? And so what?
Philosophy is all about making sound arguments to support a position. It's sales for ideas. (And UPenn's not bad, right?)
Each of the career segments involved distilling what really matters and figuring how to articulate and capitalize on it. That's exactly what's required in drafting awesome admissions essays.
I'm really good at teaching/coaching kids. I don't write their essays for them; I help them figure out how to make the best sales pitch they can while maintaining their authentic voice.
Who you are; not what you've done
Probably the most common mistake students make in their essays is that they spew a list of accomplishments and activities. Do. Not. Do. That. There are other places in your application where you can list or describe what you've done; use your essays to show who you are.
Colleges know that many applicants do a whole host of activities in high school not because they're really passionate about what they're doing but because they think the activities will make for a stronger resume. But schools ultimately care about the sorts of contributions that you're going to make once you're on their campus and then after you graduate and go out into the world as an ambassador for their programs. Whatever you did in high school is history; they want to know who you are and who you're going to be.
Write about your dreams and about how they originated. Write about things that happened to or around you that shaped who you really are. If you do write about something you did, make sure it demonstrates characteristics inherent in you that are going to make you an awesome student to have on campus and an awesome ambassador and contributor to society after graduation.
Just please, please, please don't write about how you were the Secretary (or even President) of some club that only met once a week during lunch and never really did anything meaningful, or how you were on a sports team but clearly aren't competing at a level that will allow you to make a college team. In a few months, those types of things are your past, and colleges want to envision your future.
Don't send carbon copies
Sending the same essay ("carbon copies") to a bunch of schools is not likely to improve your odds of being accepted to any of them. There are two reasons for this.
First, it's difficult to craft a single essay that is attractive to each school in which you are interested. Sure, there are some things that every school wants to see in their ideal applicants, but just like you feel a deep connection with people based on the little nuanced things that really make you click with each other, your goal is to make schools feel a deep connection with you based on the little nuanced things that highlight why you and each specific school are perfect for each other...and that can't be done en masse.
The second reason not to send carbon copies to several schools is that they are all interested in how they stack up in the various undergrad/graduate school rankings, and most of these rankings include "yield" as one of the relatively important metrics in compiling their lists. What is yield? Yield is the percentage of a program's accepted students who end up choosing that program. If a school accepts 10,000 students and 2,000 end up enrolling (so, a yield of 20%), that means the other 8,000 had somewhere else as their first pick. The rankings all like a higher yield because it means the school is first pick more often. If a school is deciding between two students, one of whom has demonstrated in their application that they really want this school (and are therefore likely to jump at the opportunity to enroll if accepted) and the other has perhaps a stronger overall application but the school isn't confident they'll come, the lean often goes to the one who they think will help their yield. So how does this impact how you write your admissions essays? It means you can move up in the pile by making each school believe that it is your first pick (and you move down the pile if they don't think they're your first pick, so even if they like the rest of your application, a carbon copy essay can hurt you!), and it's impossible to do that without including school-specific pitches in each essay.
Yes, this is more work. And yes, it's worth it.