The correct answer to this open question is the following.
What I would tell them is that never stop imagining new a better ways to do things.
Yes, this is at the very basis of creativity. To always look for different and innovative ways to do anything. It doesn't matter if is homework, a final project, or house activity.
I would also tell them that they never accept a "no" for an answer. There are no fixed rules on how to approach a situation. It all depends on the different perspectives to understand any issue and come up with innovative ways to think and act. This means to see what not everybody is seeing and saying what everybody is hiding.