As you work on finishing up your essays, don't psych yourself out by thinking the essay has to do all the heavy lifting in a college application. It is only one of many pieces. Keep in mind the two things that colleges are looking for when they read your essay:
First, can you write? Colleges want to know if your ability to write meets the academic standards of the college. They want to see that you can take a thought and develop it in a clear and organized fashion, using proper grammar. No typos, please. Your ease with language and ability to write in an engaging and thoughtful way shows them that you can express yourself effectively and that you possess the intellectual ability and readiness for college work.
Second, who are you? Admission officers want to hear your voice and know more about you when they have finished your essay than they did before they started reading it. Above all, they are trying to learn what impact you will have on their community. Will you make their school a better place simply by being a part of it -- whether that’s in the classroom, chemistry lab, a residence hall, or theater program. Colleges look for who you are in the application as a whole and the essays are one place in particular where this can be seen most clearly. So tell a story only you can tell.