Sometimes the key to successful creativity is not to make an effort to be creative, but to make an effort to capture the creative impulse as it happens on its own. Write down or otherwise record that wild thought, that single lyric or line of poetry, that melody, as soon as it arises in front of the mind's eye. Don't count on being able to remember the impulse later. So make the effort to capture it. Once that is done, if possible try to add to the impulse immediately by writing another line or thinking about where it all leads. Sketch around that first squiggle. If there isn't time for further work, at least you've captured an image of it to build on later. But if there is time right away, one may get the fullest result by allowing the inertia of the moment to carry that first subconscious impulse forward.