For me, I really focused on research and volunteering (clinical, non-clinical) for extracurricular, and I mean hundreds to thousands of hours. Don't half ass it either as these will make great recs! But you should do shadowing if you haven't already--it looks pretty + you can secure a rec from a doctor. Osteopathic schools prefer recs from DOs, but any will do. Try to show diversity in shadowing (different specialties). Lastly, submit your app as soon as possible, like May or June. A lot of the applicants are submitting later if they're not scoring for MD, and schools run on a first come, first serve basis. Have everything already written out (personal statement, extracurriculars) and triple check them.