One of the most common questions is, "What major do I choose to be a competitive applicant?" The answer, select a major that you are passionate about. You are more likely to succeed in coursework that excites you.
There are often times required courses and an entrance exam you must to take to gain acceptance into a program. Do your research early and create an action plan that will allow you to incorporate these into your major.
If you aren't sure which specific professional program you want to attend, a good place to start is with those that will grant you in-state tuition rates either through residency or contract.