If you want them to use their creative thinking to solve problems:
First, pay them enough. That darling of the dismal science, Adam Smith, had this to say about monetary motivation: "A slave on the contrary who can acquire nothing but his maintenance, consults his own ease by making the land produce as little as possible over and above that maintenance." Students who see that whatever they do will get them a pass may work just hard enough to pass. And if passing is all that they are expected to do, that is what they will do.
Then allow them autonomy, an opportunity to acquire and display mastery of interesting tasks, and a purpose for working alone or in a group.
Hey, isn't that you?