1. Apply to MANY schools and increase your options, especially if you're an average candidate. An attempt to spare money by applying to fewer number of schools may end up costing you a whole lot more later in the overall scheme of things.
2. Keep in regular (though not obsessively frequent) contact with the schools. Update letters and interest letters (must be well-timed and in good faith) to schools are important.
3. During the interview, your demeanor is just as important as what you say. By this, I mean: how composed you are, how well you listen, whether/not you're friendly and humble, etc.
4. Accept the fact that it will be a year of uncertainty, that many things will be simply out of your control, and that you may have to apply again the following year.