Unfortunately, getting a pub as a premed more about luck, networking, and timing as opposed to hard work and a superior mind.
What you can do is try and find a lab that is prolific in pumping out publications AND whose PI puts several people (ie - his whole lab) on the paper regardless of if they actually contributed intellectually to the paper (which is the usual protocol). A certain chemistry professor at my school was famous for this and shrewd premeds were able to get in his lab, prepare a few samples for NMR and wash some glassware and viola - suddenly they were the proud owners of an 8th or 9th author paper in a mid-tier chemistry journal that they could plop down on their med school applications.