It's not exactly pro forma. I haven't been accepted anywhere yet either, but from what I've read, in addition to the documentation from the school, you have to demonstrate a few things:
1) That you have a permanent residence in your home country (such as a family home)
2) That you intend to return to your home country on completion of your studies. Now it is possible to stay in America after the student visa is up, but you just have to show them that you don't intend to stay after your studies. So if you own property or have family ties in your home country that you can point to that would show your intent to return, then that would be good.
3) That you have enough funds to cover your studies and life in the US. If you get funding from your school, then they will give you documentation to show the interviewers and that should be enough.
See more information from the State department's website: http://travel.state.gov/visa/temp/types/types_1268.html