I think for school selection, you should definitely make note of the "School Selection Spreadsheet"...that thing was a godsend this past cycle for me and I'm sure many other people would say the same thing. Us applicants love knowing our odds of getting in somewhere.
The other posters talking about their increased MCAT scores made a much more substantial improvement than I did (25 to 31) but I think the overall attitude is to drastically change your study methods and approach to the exam. Everyone practices for it, but I sought out practice tests like a fiend when I studied for it the second time around. EK books worked best for me.
Interview skills: I wouldn't consider myself completely socially inept, but interviewing is tough for me because I'm overly self-critical. The stress is only magnified as a reapplicant, but the thing that I think helped me the most was talking to patients during my clinical activities (volunteering, working as CNA, etc.) and I even made a mock-interview video with my sister so I could better identify things that probably don't come across too well in an interview--facial expression is a big one. Don't over-rehearse because you can tell if you do: come up with general ideas for answers, but its okay if the wording of them changes each time you say it. Just make the major points...especially for questions like "Why do you want to be a doctor?", because if you worry too much about if you said what you wanted to say correctly then you're not going to appear genuine.
You don't mention gaining work experience (as in working in something other than research)...I think that was a huge asset to my application to do something clinical but not representative of the typical pre-med activities like research, getting a job doing tech work at a hospital, EMT. Something different. Working as a social worker/health educator provided me with a lot of the life skills and an understanding of the systems I will need to play along with as a doctor and I think adcoms saw the same thing. It will pay off big time as a doctor, and it even helped while volunteering and with my part-time jobs as well.
Having a year off also allows re-applicants to do things they were too busy to do during undergrad - I joined a community orchestra as well and just tried to relax amidst a very, very stressful second application cycle. Its important to mention these kinds of things as well.
I would hope that the rest is common sense to a lot of people, if not, that's why so many people refer to the Re-App FAQ!
But I haven't been updating it, and I think it needs work. I could use your help in the following areas: 
