The nugget of creativity is conceiving of something, and then realizing it is good.
(That is what God does in the Book of Genesis, by the way.)
Here we have two parts to the problem of how to be creative: How do you cause an idea -- that might be good -- to come into your head? And, once it is there, how can you tell whether it is good or not?
The first part is not difficult. Ideas or thoughts (I'll use the terms interchangeably) flow through the mind continuously. The mind itself is not continuous, but when the mind is in action, thoughts are present. Even the idea, "This is not an idea," is an idea.
Ideas are plentiful. If the mind is aware of something, it is a thought. This is why we have words for different parts of our experience as sentient beings - we are aware of sensations of experience that are not ideas. The mind does not feel a quivering in my muscles, or any other sensation. There are sensations that are pre-thought. They appear to cause some thoughts. The sense that "I" (the subject) am feeling or experiencing things that are not "thought", provides the sense of continuous existence, between discreet thoughts. But the mind-part of my being is only manifest as discreet thoughts. Ideas that could be good are always available when one is thinking. But much of the thinking process in adults is taken up with denying that one is having certain thoughts. This is unfortunately due to our socialization process. It is difficult to evaluate any ideas that you deny to yourself you are having. If you can get over that hurdle, you should have access to plenty of ideas to choose from.
When is an idea good?
We usually think and idea is good when it makes us feel good, or hopeful. Business people think an idea is good when it makes money. It would be nice to think that our evolution has lent us to the ability to to recognize good ideas in terms of what is likely to be successful. If you think something is likely to be successful, then you feel hopeful about it.
Is the following true? that if the idea makes you feel good, it, or whatever it suggests, is more likely to be successful? Perhaps there is no connection. But some people do seem have an innate ability to recognize good ideas. It makes sense that having such a recognition feels good. So then, for some people, at least, ideas are good when they feel good.
The person who recognizes a good idea, is inspired and energized. If this allows the person to put the idea into effect, then it is much more likely to have been a good idea than if it had died on the vine. Furthermore, it can be tested and modified, allowing it to become and even better idea.
I am led to the conclusion that good ideas are those that make us feel good, and creativity is recognizing good ideas.