The basic way to do this is to quite simply not listen to us (we being the college experts whether Yale Tutors or another tutor or your guidance counselor or English teacher or any other so-called expert). We often run into students who are loathe to take our advice. We had, for example, a potential law school student who wanted our help putting final touches on his essays and personal statements i.e. fixing up sentence structure, word choice, etc. We cut the session short so as to save him money and told him that his essays were not sufficiently compelling. He should try to write some more essays and we could take things from there. He didn't like our advice and cited how much his mother laughed at one essay and how much his sister appreciated another essay. He ended up trusting his mother's and sister's judgment, rather than ours (he didn't write any other essays) and was not admitted to a single law school.
The moral of the story is not that you can't trust your sister and your mother! Rather, it's that there are many people who can appreciate writing one way or another including your family, but that doesn't mean that they have a good idea of what's unique and interesting and well-written from the perspective of a college admissions committee. You need to get feedback on any essay you write from an "expert," someone who's read a lot of college admissions essays and has some idea of what the admissions committees are looking for. It's very hard to have a good perspective on your own writing. This is particularly true for personal writing--what you're experiencing may be very important to you, but it could also be something everyone goes through and so not interesting for any particular person to read (since they've been through that; it won't express anything unique about you). An editor will give you perspective and guide you.
A second common pitfall we run into is the summer essay. Many of our students come to us in the early fall with a college essay they've been working on for months which they gingerly hand over to us as a treasure. After three minutes (we've read a lot of essays), we have a tough job: to tell our student that we know there are better essays inside him or her. To counter this phenomenon, we have a process we now use with our students...
This step is fairly obvious--you'll need to know what the essay topics are before you can write on them. If you're having trouble with your list, you can start work on the topics for the common application (a single college application accepted by hundreds of colleges).
From this list, try to figure out how many essay topics overlap and where they overlap. If you're filling out ten college applications, you shouldn't have to write ten separate full essays--there should be a lot of overlap (you're allowed to send the same essay to multiple colleges). We're usually able to get our students down to two or three longer essays that they'll have to write and send in to colleges.
Brainstorm by yourself or with someone as to what are potential things you could write about for your college essays. Try to have at least three ideas for each essay you'll have to turn in. If you're able to quickly put together an outline of a potential essay, do it. If you're further able to discuss these topics and or your outlines with an "expert", also do it. The expert would already be able to guide you away from the essay on how you're ready to create world peace to an essay on why you don't like to help your mother wash the dishes.
Topics to avoid are anything political, anything really broad in nature like world peace or world hunger, anything controversial like abortion or sex education, and any topic that anyone could write the essay on that you intend to write. You need to pick topics on which you can write an essay that no one else in the world can write; an essay that depends on who you are, your thoughts and your experiences.
Here you need to put, say, three 2-hour blocks into your schedule for the week. For each block, sit in front of a computer (or with pen and paper) with some idea in mind (from step two) written at the top of the screen and start writing about it. Don't worry about sentence structure or organizing your thoughts into proper paragraphs. Try to just focus on expressing what you're thinking of feeling accurately. Do this until you have at least a single page filled up, and do continue beyond that for at least two hours. If you're having trouble writing anything, brainstorm and write examples or related thoughts to your initial idea at the top of the page. Do not get up from the computer until you've filled up at least one page.
Repeat this free-writing essay exercise until you have several different essay-like writings. After two weeks, you should have six pieces of writing which is pretty good.
Take your essay-like writings from the third step (your six pieces, say) and give them to an "expert". We need the "expert's" perspective now. Ask the "expert" to tell you what particular ideas, sentences, paragraphs, or even entire essays express something interesting and compelling. The "expert" needs to look for what parts of your essays expressed something sincere and unique, that he or she wants to read more about. It could be a single sentence or it could be an entire piece you've written. The "expert" may find a single observation compelling in an otherwise boring essay, and that observation could be the kernel of a new and actually compelling essay.
Here are some examples. From a fairly typical essay about a student's summer volunteer work with a medical clinic in Latin America, the student had a single sentence on his visit to the home of a sick person and her silence upon seeing how this person lived. We told her to try to turn that single sentence or self-observation into an essay--write just about that single visit and not the whole trip. Another example is an essay on a college visit which was a bit nauseating in its praise of the college. There was one interesting bit, though, on impromptu student-to-student teaching. We asked the student to write more on that experience and anything else on how that college fosters students teaching other students and generally studying together or socially (and why that was an attractive thing). We believe the student ended up with a much more compelling, thought-out essay on what made that college and his own interest in attending it unique.
Now that you have the raw material or rough draft of a great or even a few great college essays, you have to make them perfect. Now is the time to use the spell check and even the buggy grammar check in your word processor and more importantly the grammar and style check skills of your "expert" and or any other competent writer. Pay attention to word choice, sentence structure, and the general flow of the essay. At this point, you can obsess a bit about every little detail. The sentences should flow together well, and you should use one or two more difficult vocabulary words in the proper context and accurately (don't use more than one or two or it'll be obvious you're trying to show off). Revise an essay then sleep on it for a day or two before doing another revision--time will give you perspective on your writing. This is actually the easiest part of the whole process even though it may take the longest amount of time and require a bit of painstaking attention to detail.
Don't get attached to any particular essay you write. Write multiple free-written essays to start with. Don't start perfecting your essay or even revising it until you're certain your raw ideas and writing are unique and compelling. Try to find someone who has experience with essay writing in general and particularly college essays to get their perspective on your writing. Aim to be sincere, thoughtful, precise and observant in your essay. Be sure that your essay is uniquely yours--no one else in the world should really be able to write it other than you; it shouldn't be generic in anyway.