Learning how to motivate a creative professional is tricky. Most of them want to work at something they enjoy doing, and they will put off or find ways to avoid things that they don't enjoy doing. While this happens with nearly every employee, creative people are much likelier to get in trouble from it – and are much likelier to leave the organization if they're called on it. As a manager, talk to your creative team about what they're working on, and look for the hedges for things they don't want to do; then find a graceful way to either get that task out of their hands once they've gotten bored with it, or explain that there is nobody else to do it.
Creative staff members are motivated by professional accolades, and fun, rather than paychecks, promotions, or 'silly prizes'. They are people who took Chuck Yeager's advice, and discovered what they loved, and then matched their life style to it, rather than finding what they could do, and letting that fund their life style. As a result, creative people are going to be more independent in their thought, their attitudes and their mode of dress. Your creative people will decorate their work space. Learn to live with it if it isn't disruptive.
When it's time to set standards, putting punishments on creative people is a disaster waiting to happen. It doesn't work. If you must 'manage', manage from the front – set standards and make a habit of meeting them as a public example. Nothing causes you to lose credibility faster than setting a standard you cannot meet yourself. Likewise, rigid time schedules are, 90% of the time, unsustainable for your creative team. When they're on fire with a project, they'll work 60 to 70 hours a week. Other times, they may show up 20 hours a week, or they'll show up at hours when nobody will disturb them; in one organization we surveyed, the principal internal artist made a habit of showing up at 5 AM every day, so that he could leave shortly after lunch – and by doing so, generally avoiding the meetings and pep rallies that he considered a waste of his time. (This creative also studiously avoided accepting anything resembling a promotion.)
Remember that fun, and a challenge, are important. The best way to burn out your creative staff is to make them do something that's 90% identical to what they've done before. Other people like staid, repetitive tasks, and knowing exactly what's expected of them. Creative people like knowing that they're doing something different and challenging. The same sorts of environments that make ordinary office workers cringe are what creative people thrive on. And when your creative people are flagging, start talking about the next project a little bit – so that they can use it as an incentive to finish off the unpleasant parts of most projects.