Do your research and show how you can contribute. If you know what my products are, who my users are, and have insights for how to improve the products to better meet their needs I'd give you bonus points in the interview.

Working with teams is also important. I'd definitely look for a portfolio like the other commenters suggested, but also that you worked with others on some of these projects. Going from hacking something out yourself to managing a product built with other busy people is a big step.