• the use of imagination or original ideas to create something; inventiveness.
  
  

I would describe creativity as the ability so see something new and turn it into an idea. It is a combination of observing, thinking and acting in an original or inventive way. We are all born with a creative brain. As children we usually see situations in a surprising way and we come up with the most original solutions. But throughout the years we learn how to 'behave', we become less spontaneous and creative promptings disappear. The aptitude is still there, but they won't come up in our consciousness anymore. 
We established the fact that we can learn how to be creative, since we already have that ability in us. What can we do to learn how to use the creativity again?
Be bored. A full agenda and stress are deadly for the creative brain. Let go of all of that and make long walks on your own and consciously look at everything you see. This creates energy and space for new ideas.
Train your imagination. Creativity is literally in your brain. The more connections there are between your brain, the better you can look at something in different ways. You can consciously increase these connections.
Dare to fail. By trying things out, you put the process into action, and a flow arises. That also means that it could fail sometimes. If this happens, be nice to yourself and start again. Don't ask yourself if it's going to work during the process. That is a true creativity killer.