The following attitudes and activities seem to be necessary for creative thinking, and have been observed in all truly creative people regardless of profession.
Training and practice of right brain functions
Suspension of judgment; making disconnected jumps in thinking
Openness to new stimuli, new ideas, new attitudes, new approaches
Willingness to take risks; making "leaps of faith", lessening inhibitions
Freedom in subjective thinking; expression of emotions and personal realities
Intuitiveness, "playing hunches" to generate spontaneous ideas
Freedom to make outlandish responses; rejecting fear of being "wrong" or unconventional