- Be open to non-engineering roles, possibly to the point of actively seeking them out.

- Having and showing an interest in the industry I work in. Product managers are focused on solving customer and business problems in ways that create value and solve pain points for the customer and make money for the business.

- Developing a sense not only of the best technical solution to a problem, but also what business opportunities that solution opens up. Even when answering technical interview positions for my new job I would always back up a level and explore some other possibilities or motivations.

- Learn to communicate potentially technical information to non-technical people. By this I mean concisely expressing problems, hiding details that aren't immediately important, translating "side effects" into consequences.

- Demonstrate an ability to dig deeper into customer motivations and needs. They will often express what they want in terms of what is immediately visible. Sometimes you have to dig deeper so that you can come up with a design that solves their real underlying problem.