What to do with my post-bacc sciences and a word about them (med school)..

[cookderosa]

^ What davewill said, plus shadowing and clinical exposure, and extracurriculars including substantive volunteering.

If a basketweaving major existed, it's realistically possible basketweaving majors would have a high med school admission rate, not because anything about basketweaving was uniquely good preparation or uniquely favored by med schools, but because the small and unusual population of basketweaving majors who then went on to qualify for and apply to med school tended to rock their science courses and MCATs.

Do what will help you rock your science courses and MCATs, and the sort of extras named above.

True story. Med schools want the applicant to have exposure to the clinical setting prior to starting. While shadowing is clinical in nature, it's not considered clinical interaction, so they also like when students volunteer at free clinics or other routes of patient care in addition to shadowing. 

While a good MCAT score doesn't guarantee a good doctor, it shows the school that the student is capable of handling the material to come.

I spent 2 years volunteering 2 nights a week at a free clinic. It was part of the reason I decided NOT to pursue nursing/med, however, it was a WONDERFUL job and a WONDERFUL experience and the only reason I left is that we moved from IL to NC. If I were still in IL, I'm sure I'd still be there. It is really important, in my opinion, that you do this to see if it's inside of YOU as opposed to it looking good on your application.
Once you're touching and smelling and helping and interacting with people who are at their worst, you'll find out a lot about yourself. I found that I didn't like hurrying, I didn't like the risk of error, and I didn't like the necessity of being above the patient. I've worked as a teacher most of my adult life, and that's a better fit for me. Had I pushed forward, I realized that the career change wouldn't use my strengths and it tapped into a lot of my weaknesses. I might not have had that same insight in my 20's.
The flip, is that if it WAS a good fit for me, I the experience would have also been golden on my application - I made a lot of inroads / network, spent quality time with doctors and nurses who would have written letters for me, and for sure would have had opportunities for employment after. None of that would happen in a simple job shadow. (I did one of those too - I did 40 hours with a NP - not the same)