How do you think outside the box? Can it even be learned/practiced?

So I don’t consider myself an “outside of the box” thinker, at least when it comes to most things. This is evident in my studies, I am going for an mba and it seems this type of thinking is often called for in the program. Problem is, I’m always short for ideas and am starting to think I’m just not cut out for business/marketing. So is this a skill that can be learned and if so how? Any pointers? Are you just born with it? I can think outside of the box for certain things, like anything having to do with general computing.