Three is a good number

Whatever the topic, if you really don't know what to do, start with the number three.

If you don't have a plan, divide the available time into thirds. The first third is for exploration, generating initial ideas, figuring out what to design. The second third is for doing the heavy lifting of developing the design. The final third is for refining the design towards a desired result.

Since you don't know whether you'll get it right the first time in each of these phases, you iterate them, at least three times. In the first iteration you can afford to take risks and make mistakes. In the second iteration you will have a much better understanding of what you should have done to begin with, and can do that instead. The third iteration is for getting closer to something good enough.

What do you iterate? Not one, not two, no points for guessing that you should do at least three parallel, significantly different design alternatives. Each of the three alternatives might have at least three main benefits and three main costs, and so you will get three times as much information about their value. Evaluate each design with the help of three different stakeholders and you will again multiply the value of the information by three.

Should you devise a more fine-grained plan, do more iterations, generate a wider range of alternative ideas? Absolutely, if you can. Often, though, people do the opposite: they make no plan, do not iterate at all, proceed linearly with a single design proposal, and in the end risk total failure. Three is not a magic number. It is a good, good-enough number. With at least three of whatever it might be, you will get unstuck and get ahead.