Creativity is less likely in familiar surroundings. Find a novel place to work—off site, outside, in someone else’s workplace. Getting away from your normal work space also minimizes interruptions.
Provide an atmosphere where people can take risks without criticism. Foster a willingness to test new ideas and alternatives, and encourage the free cascading of thoughts. Encourage humor, fun, and positive interaction.
The best solutions may not emerge quickly; get commitment for the time and effort the problem deserves, but do set a reasonable time limit.