I hope you're able to help a lot, BABS! I followed you and the other people in the 2012-2013 thread and it's been really helpful reading all the stuff on there.
Any tips on secondaries and interviews?
For secondaries, always research the schools enough to have specific examples why you want to attend. Try to fit each schools' mission statement and write about how you do just that. Stress the activities that fall in line with it. For UW, this is medicine that has an underserved or rural focus.
If you check out last year's thread, you will find people that had 4.0s and 38+ MCAT scores that were rejected pre-secondary! UW does give a little slack to instate people on receiving a secondary/interview, but I think they are still looking for the same qualities/activities to give out an acceptance. I had a bunch of WA friends apply and only one was accepted the previous year (planned to help Islamic patients because they are underserved but ultimate did not matriculate to UW) and one this year (planned to do rural medicine and will matriculate). Both had their background to highlight their passion to do what they said that also fit the mission statement.
For interviews, practice answering questions aloud. It sounds stupid, but do this because you can practice stringing together phrases and sentences. You can find what sounds best together. When I thought out my answers without saying them, often times I would think incomplete thoughts and say it was enough and that I would fill in the details in the interview.
You should also make sure you answer their questions. Again, this sounds stupid but practice doing it. I know how nervous you can get and you can forget the question while answering and go on a tangent but try not to. You should also have examples to back up what you say. Like if they say, "do you support (or like or have criticisms of) the ACA?" then don't just say yes or no. Say "yes I do for these reasons" or "no, I don't think it goes far enough in this way" or "no, it is government overreach in this way and may..." Etc. All schools are looking for how you think and these questions show your thought process.
Speaking of thought processes, for interviews you want to think aloud! They can only see the thought process if you do it aloud. Another way of putting this is to give a bunch of reasons for your answer and then saying that all of these are the reason why you have those feelings. For the roll play question, this also means asking questions of the situation given to you. They purposefully leave out some details that may help you but will freely give them to you if you ask for them.
Also, UW has pointers on their website for interviews. For example, they say they want to hear you repeat the question after they ask them. I agree with this because it helps you stay focused when answering and it really helped me not go on tangents.
The final piece of advice I can give you, and this isn't for UW because their interviews are different from other schools, is that if your interviewer likes to talk or go on tangents, don't interrupt or try to steer the talk. Just relax, have fun and go on the tangent with them (this may seem to contradict what I said earlier but notice earlier it was about you not going on a tangent while answering versus your interviewer). You want to leave with the interviewer liking you and small talk is a great way to achieve this. If you try to steer the direction of the interview you may seem like you are power hungry or like to have all control, if you interrupt you may seem impatient, etc.
Sorry if this doesn't make sense, I can try to clarify anything if you have questions. I know this is a stressful time, but relax as much as you can. It is a long process. For example, I applied June 2nd, I was invited to complete the secondary July 5th, got an interview on August 6th, received the date of the interview on September 13th, interviewed on October 9th, and then wasn't accepted until March 21st! That was 9 months of waiting for me. I know other people got accepted sooner, but don't worry if you get strung along like this. Just keep writing them LOIs when you have enough details to do it.