Determine what you need in the residency program you are looking for. Location, specialty, instructors and the education the residency provide are key in finding the right one for you.
Meet with the faculty adviser for your current residency position and ask for her help in finding a program that is a better fit for your needs. Her contacts in the medical field may be of great assistance.
Call and send inquiry letters to residency programs that interest you, even if there is no current opening. It doesn't hurt to get your foot in the door, just in case an opening comes available later.
Search for residency vacancies on your own. There are a number of online tools available (see resources below) to assist you in this search.
Apply for all residency vacancies that interest you. Just like when applying to college, the more applications the better, since you may not get your first choice.