In addition to tibbett's point (expressing technical accomplishments in terms of their value to the business), do some honest introspection on your value to you

In addition to tibbett's point (expressing technical accomplishments in terms of their value to the business), do some honest introspection on your value to your peers. I'm really just elaborating on Ms. Botros' article here, but for example you want to ask yourself these kinds of questions: Do you improve the skills of the people around you? Do you identify and help resolve barriers faced by your peers? (This doesn't always mean fixing things yourself!) Do you improve the environment and culture where you work? Can you work collaboratively to establish a vision for change? How do you gain the buy-in of your peers when it comes time to implement change? Internalizing these answers will prepare you to steer the conversation onto the skills that you know are important for the role.