As a chief resident I just went through the ranking process with the leadership of my program. In our program the first thing you have to show is the interest in pathology. As medical student you can do an elective in pathology or even away rotation in pathology. If you have been part of some research project it helps, but to a degree. At least in our program, scores does not matter much, as long as they are above certain threshold (I think 200ish) and you have passed the steps in first attempt you are fine. The second thing you have to show to be ranked high is the interest in our program (ties to the region, knowing what the institution is and what faculty do and why you want to study/live here). The third and also very important issue is your communication skills on the interview day, it seems obvious, but if you do not have a clear enthusiastic story about you on interview day than on the ranking conference the interviewer will basically say "I didn't feel he/she would be a good fit for the program, I do not have a clear picture about him/her. Something is not right - let take another look" or something along these lines and it usually means you are going down the rank. This year we had quite a few US grads with good scores ranked lower than 20 (which historically is not matchable to our program) due to interview day performance and I think we did not rank 2 or 3 US grads at all due to the same issues. Overall spirit has changed from "we need to fill not matter what" to "we would rather go unfilled this year than have a bad resident".
To conclude: do the elective and do the away rotation in pathology this will get you the most of the bonus points to match into good pathology program. And pass the steps, ...