Imagination is a very high sort of seeing, which does not come by study, but by the intellect being where and what it sees, by sharing the path, or circuits of things through forms, and so making them translucid to others.
Opinion involves belief (for without belief in what we opine we cannot have an opinion), and in the brutes though we often find imagination we never find belief.
If the imagination is to transcend and transform experience it has to question, to challenge, to conceive of alternatives, perhaps to the very life you are living at the moment.
Imagination is more important than knowledge. Imagination is the language of the soul. Pay attention to your imagination and you will discover all you need to be fulfilled.
Be what you would seem to be - or, if you'd like it put more simply - never imagine yourself not to be otherwise than what it might appear to others that what you were or might have been was not otherwise than what you had been would have appeared to them to be otherwise.