Here are my big takeaways from this book:
[Rule 5] Learning to say “no” to customers – this is perhaps the one takeaway I’ve heard time and time again from PMs. Understanding your customers is paramount, but that doesn’t mean every detail and request from them is appropriate for your product. This is much easier said than done, but I think the most important skill in the practice.
[Rule 16] Get out of the office – this rule is to get a better understanding of the customer viewpoint, but I think it is probably one of the most misunderstood…amongst your colleagues. For all other roles on a team in an Agile setting, staying in the office is typically a rough indicator of commitment, work output, and availability. It may not always be clear why you are spending time outside the office, especially if you are unreachable. As a PM, it’s important to stay available as a PM outside of the office because the team is relying on you.
[Rule 35] Act like a child – the book describes the core of this rule as someone who continuously asks, “why,” such as in the common “five whys” exercise. I think this rule could further extend to physically getting a child in front of your product. One of the best user feedback sessions I’ve ever had was when testing an iOS app that I developed with my young cousin when he was about 8-10 years old. I asked him to perform an action on the mobile app’s map screen, and watching him use the wrong buttons told me that I needed to simplify the UI and remove unnecessary features.
Conclusion: 42 Rules of Product Management is a good reference to pick up from time to time as a PM. It’s a bit light on examples but can give you a good exercise or two when you really need it.