Creativity can be thought of as a combination of two things: A random idea generator, and a nonsense filter. Generate new random results ideas, filter out the nonsense ones, and you’ve generated good ideas.
Creativity also requires information. And Information is discovered. We can only generate random ideas from what we know. We can't imagine something we've never sensed, or know. You can't imagine a color you've never seen without recalling known colors. You can freely mix ideas due to your imagination.
But when we discover new information, we must decide whether the information is useful. Otherwise the information is considered noise.
We give weight to decisions: time spent pondering, considering, and the more weight we give, the better the decision. Almost always the idea is measured in usefulness.