"Dare to be silly" — that's a rule, courtesy of Paul Krugman, that I should barely have to elaborate on. The evocation of it alone should be enough, whether or not you're a Krugman fan (or a Weird Al fan, for that matter), but the context for the word "silly" is worth detailing. Krugman found that the really valuable work to be done was not in making safe but unadventurous extensions to existing theories, but rather to take bold, potentially foolish-seeming steps — what he deemed the use of silly assumptions:
What seems terribly hard for many economists to accept is that all our models involve silly assumptions. Given what we know about cognitive psychology, utility maximization is a ludicrous concept; equilibrium pretty foolish outside of financial markets; perfect competition a howler for most industries. The reason for making these assumptions is not that they are reasonable but that they seem to help us produce models that are helpful metaphors for things that we think happen in the real world.
In other words, the silliness is a function of the fact that such work is often open to ridicule for trying to look at things differently, and derive a useful model from that perspective.
This one's tougher to map onto creative work, in part because daring to be silly is such a fundamental part of being creative in the first place. But then I thought about it this way: What kinds of being silly in the creative sphere are the sorts of things that are greeted too often with incuriosity, and by whom? That's a tougher question to answer, and it's so broad and far-reaching that I'm not positive any one answer would fit.
That, in turn, tells me something about how to approach this whole exercise. Whatever it is you do, look at what your peers are doing and then ask themselves: What are they not doing? What could I do that might conceivably broaden my scope and enrich my understanding, but which they would probably giggle at and walk away from, shaking their heads? I had my own answers, but the point is to find your own.