Here a few habits that I think are desirable to have. If you have a few of these at least you might have a better chance of success.
1) Intellectual curiosity. Usually someone will read beyond what they have to. Imagine a student in a graduate program who only reads assigned readings and lists. Contrast that with a student who has her own lists, an intellectual agenda that goes beyond what the professors are telling her how to read.
2) Intrinsic motivation. Imagine a person doing scholarship in order to earn tenure or a degree. They are attempting to come up to the institutional standard. That is fine, but what if you thought of the institutional standard as a bare minimum, and decided to go far beyond that?
3) Serious outside interests. So take the case of a psychologist with a serious interest in classical music, for example.
4) As a corollary, not everything will be instrumental. The interest in music for the physicist may or may not make him a better physicist. Who cares? If you make only instrumental calculations then you might miss out on something later on. For example, I am improving my Italian, but the reason why is not evident to me yet. There may be a reason but it is one I cannot calculate.
5) There is a kind of ownership of one's own field. I don't mean a proprietary, "get-off-my-lawn-kids attitude," though some people have that too, but rather a sense that one should know what one is talking about. Just having a base-line competence and sense of ownership will allow you to be part of the conservation in a field very quickly.
6) Not letting minor projects get in the way of major ones. So you will find people who have interviews, translations, and other "bird-dropping" publications in place of refereed articles and book chapters.
7) There is an idiosyncratic or paradoxical cast of mind that doesn't accept the conventional wisdom, or views it simply as a starting point that may or may not be correct. A creative scholar will think against the grain.
8) At least in my field, you have to have prose. In other words, by writing well you automatically have huge advantage over the average person.