What to do to increase chances for a grad school CS program?

<p>So I'm currently starting my sophomore year as an undergrad in some business school. My current plan of action is to be a math major with a CIS minor to eventually apply to MS mathematical finance or financial engineering programs. Yet I am wondering what can I do to prepare for a good grad school CS program on the contingency that I fall in love with the computer courses. What can I do to maximize my chances?</p>