It’s impossible to describe it, but you can list the moments when it appears.
For me, creativity is fertility during professional activities. Sometimes it’s released while doing nothing. It’s untraceable, but one can look for it as if through a haze, or it will find you when you start to pursue your goal.
Remember how you swung on a swing and you finally made a full rotation. You couldn’t resist the idea. Did somebody make you think of it? You just liked it that way. And here we are on the right track of creativity.
Creativity supposedly comes from thinking, but in my opinion, thinking is only a witness to it.
We start designing: research, analysis, assumptions… Everything goes in a linear order. It comes to the creation and everything starts to fall apart. Why is that? Creation has no rules. Unless you follow some pattern, which resembles other existing solutions.
Sometimes your first thought about the project is the best one and you know that! At other times a concept after a concept comes to your mind, but the realisation seems far-off. Only after you give up on finding a longed-for pattern, it will appear intentionally, just by chance.
It would be quite a job to find theories of creativity, or some system, scheme of action.
If I were to stimulate my creativity anew, I would do so just by observing children.