Well, first you have to know what your ultimate goal is. Second, check if you've got the right skills. Third, know why you really want to get promoted. Lastly, work on the skills that you don't have that will make you sucessfull once you apply for that position.
In addition, mastery of basic skills is very necessary. Kung maayo ra ka manugo pero dili ka kabaw mutrabaho, you'll lose your direct reports' respect. Trufax.