My advice would be to read a lot (the student BMJ is useful for this) and keep up with topical medical news so you are aware of any prominent health topics.
Try to obtain part-time work as a HCA. In fact, I would go so far as to say the more the merrier provided it doesn't impact your studies.
There are various places you can submit essays, though they take some fairly strenuous effort and they would need to be good... Still, they would be worth doing. You can discuss what you learned in interview if anyone happened to ask, say, along the lines of: how would you demonstrate your commitment to medicine?