Choose the topic wisely: When you select your topic, make sure it is something that is easy for you to study, understand and elaborate. A difficult topic may lead you to doing your job half-heartedly or badly.
Varied resources: Give more importance to the diversity of resources. It may be tempting to get all your information off the internet, but books, magazines and journals may have a lot more in store for you.
Learn from the best: Study other dissertation samples and see how people who have achieved great things, do it. For all you know, you might land up with something that is written about your own field of study and may be able to discover yet another source of information.
Make a mentor: You already have an evaluator, but look for a mentor, some who has been there and done that, someone who might be able to understand and explain how you must tackle the dissertation without getting hassled.
Excelling at a dissertation is not a very tough task, all you need is some amount of innovation and the drive to achieve something that is challenging and requires an extra effort. There have been achievers before you and people will keep achieving, but how you make your dissertation is what matters the most.