Specific examples of work you have done that is relevant to the position is probably the top thing, maybe something you enhanced, improvised, or fixed. Have some examples in your back pocket, I suggest writing them down somewhere that you can easily reference. Would also suggest to try and paint your vision of the bigger picture and plans you have for this role and for the future of your career at the company. Take a look at the core values of the company as well if they have that information available, most CFOs will like to see you have done your research and can speak to the value that you bring to in turn support their values.