The Imagination merely enables us to wander into the darkness of the unknown where, by the dim light of the knowledge we carry, we may glimpse something that seems of interest. But when we bring it out and examine it more closely it usually proves to be only trash whose glitter had caught our attention. Imagination is at once the source of all hope and inspiration but also of frustration. To forget this is to court despair.
It is the care we bestow on apparently trifling, unatractive and very troublesome minutiae which determines the result.
The most effective experimenters are usually those who give much thought to the problem beforehand and resolve it into crucial questions and then give much thought to designing experiments to answer the questions.