People will be most creative ...

People will be most creative when they feel motivated primarily by the interest, enjoyment, satisfaction and challenge of the work itself.
 Teresa Amabile

Quotes from the same author

Creativity depends on a number of things: experience, including knowledge and technical skills; talent; an ability to think in new ways; and the capacity to push through uncreative dry spells.
 Teresa Amabile
If you facilitate your subordinates' steady progress in meaningful work, make that progress salient to them, and treat them well, they will experience the emotions, motivations, and perceptions necessary for great performance.
 Teresa Amabile
Most people aren't anywhere near to realizing their creative potential, in part because they're laboring in environments that impede intrinsic motivation.
 Teresa Amabile
People can certainly be creative when they're under the gun, but only when they're able to focus on the work.
 Teresa Amabile
Track your small wins to motivate big accomplishments.
 Teresa Amabile