Honnestly I mainly enjoyed the Essays part compared with the Gmat section. Gmat was the worst thing that I've ever done for my application because I've not enjoyed doing this and also mainly because I took the test 4 times
For your essays, before to do anything you should llok at yourself in an honnest way and try to see what are your strong points and your weaknesses. The idea is to point out your strengths and to make your weaknesses look better.
Usually you will always have 3-4-5 questions for each school, try to see how you can answer those essays and at the final show all your best qualities and strengths...don't spend 2 essays on the same thing, it's useless and don't forget that actually 4 questions to show your entire profile to the board of admissions is not so much, you need to be precise and especially very concise, that's why I've always found that Stanford Essays were the best because there are only 2 of them and it's very difficult to attract the attention by only answering 2 questions
There is no candidate that is not interesting, however it definitely depends on which angle you choose to introduce yourself and this also depends on which kind of schools you are targeting. Take your time concerning your strategy, that's the most important point.
I am sure many members would also be able to give you suggestions if needed, however we would need more information about your profile...
Good luck anyway