I think this applies to many creative pursuits, whether with a pen, paintbrush, a camera or even a glue stick...
"...No one can advise or help you–no one. There is only one thing you should do. Go into yourself. Find out the reason that commands you to write; see whether it has spread its roots into the very depths of your heart; confess to yourself whether you would have to die if you were forbidden to write. This most of all: ask yourself in the most silent hour of your night: MUST I write? Dig into yourself for a deep answer. And if this answer rings out in assent, if you meet the solemn question with a strong, simple ‘I MUST,’ then build your life in accordance with this necessity; your whole life, even into its humblest and most indifferent hour, must become a sign and witness to this impulse. Then come close to nature. Then, as if no one had ever tried before, try to say what you see and feel and love and lose."
-Rainer Maria Rilke, February 17th, 1903
via Sara Remington