A key element is picking a topic you are passionate about. Otherwise, it's very tough to put in the necessary time researching and writing.
Yes, that is absolutely essential. Even if you must write on an assigned topic, find something about that topic that genuinely interests you and then use that as the narrow focus of your paper. It's worthwhile to spend time on this aspect of pre-writing before plunging into other tasks. However, you may need to do some preliminary research in order to learn enough to know what will interest you.