If you are having trouble finding your “voice” – or if you are uncomfortable writing about yourself because it sounds as if you are bragging, try to write the first draft in third person (he, she), as if you have conducted an interview with yourself. It takes the pressure off – Later, you can decide whether you want to change everything to first person (I, me) or if you want to leave it as is!
Remember, the essay should demonstrate your ability to express yourself well and persuasively in writing; it should be an effective tool in helping the admissions officers to decide to accept you!