Application Essays are one of the most important criterion on which your admissions are decided. Application essays act as a medium through which the admissions committee decides how fit you are to be a part of their class. How good you are and how eligible you are to manage a team. Of course, its all in the way you present yourself.
Packaging is everything You can have a dashing profile, a tremendous reco and yet, if you send out a lousy application essay, it'd be as easily rejected as easily the Indian team came out of the cricket world cup. No fight at all. The truth is when the admission committee is looking at an essay, they know that this is going to be a botched up version of you. They know that for every activity you have done, you would be presenting it as a big deal. So when they see something like
"I was a part of one thing at a particular point of time" they tend to think that you havent done anything at all. Rather they would be expecting to see something along the lines of
"I was an important core member of this committee which was detrimental in doing this or getting such and such a thing done". So when you are writing something make sure there is a punch to it.
Answer to the point and highlight your strength using points around itThe question maybe as simple as what your passions are. You can say stuff like you love dancing or you love music, or you love taking part in an cultural event. The difference between saying
"I love taking part in cultural events" and
"I love involving myself and giving a 100% to anything I am involved in" is that in the first case you highlighted a passion and in the second case you highlighted a passion and added an extra dimension about your personality that you the kind of person who would like to give a 100% to whatever you are involved with. Having said that you should also be careful that you dont cross the thin line between exploring the points around the question and deviating from the topic. In the above example after having said the latter if you say
"I think every person should give a 100% to whatever he does", then that would be deviating from the topic. Stick to what you do and stick to what you like. Passions like singing and dancing and the like seldom amuse the admissions committe, since they arent looking for fine arts students.
The Admission committee expects a certain level of professionalism from you. I say you give it to them.Admissions committee expects you to be formal. They dont give you points for being whacky. They dont expect you to be original, but they do expect you to be honest. If you think a particular sentence is cliche, dont think twice, say it. There are no cookie points for being unorthodox. You have to professional and have to give them the feeling that you would gel well with the rest of the class and not try to be oversmart or try to outwit them. Most of the Indian students who apply are pretty young and one thing they have to make sure is that they do have to put in some maturity across to the admissions committee.
Its 4 a.m. here, more to come soon... 
