I have never published a research paper or abstract. I have never presented a poster. I have no extra graduate degrees. I didn't take any time off before or during medical school. I have done no mission trips. I have average exam scores. And I'm not even that good looking. Nevertheless, I have managed to successfully carve through the medical training system. How? By being interesting.
My background is in... well, lots of things. In high school, I won poetry contests and graduated at the top of my class. In college, I adopted ultra-marathon running and triathlon. In medical school, I changed focus to social endeavors. By residency, I was focusing on dancing and creative writing.
So, how is any of this relevant? Because I am considered accomplished, versatile and, therefore, competitive. The key isn't WHAT you do in most cases, it's that you succeed at it and are always moving forward. So, why not do things you love?
The goal is to move your hobbies out of the "Hobbies" section of your resume and into the "Honors and Awards", "Experience" or at least "Activities" section and to be able to talk about them in your essays and interviews.
If you're in medicine, you must be fairly smart and talented in some way. By being marginally creative, utilizing your own strengths and setting specific medium-term goals, you can gain noteworthy achievements. Let's give some examples: let's say you like running. You decide to run a marathon this year. Problem is everyone runs marathons. Not very unique. There's a few options here. Option 1: why not run 3 or 4 marathons in a couple of months? You're already trained for one. The difference between 1 and 4 marathons in terms of training? Not much. The difference on a resume? Enormous. Now, you've become a 4-time marathon finisher! Option 2: why not wear a costume? I once broke the Guiness World Record for Fastest Marathon Dressed as a Baby. There's a whole group of world records for running in costume -- or, better yet, you can make up your own! And it's free to apply.
Not very athletically inclined? Maybe you just want to party? Why not throw your own events? You can organize events either for a cause or just charge admission and donate the money to charities. Suddenly, you went from doing nothing to being an Event Planner and a philanthropist.
If you like creative writing, major scientific journals have creative writing sections to which you can submit and get publications without doing research. If you play an instrument, why not do it for kids at a hospital? The list goes on and on.
Being a strong applicant is as much about being a well-rounded person as anything else. Some people really enjoy research, and that's great. If you don't, try to spend some effort looking for opportunities to achieve in others spheres to show strong a candidate you are. With any luck, the only question anyone will ask is "How did you have the time to do all that?!"