What makes a "well rounded" applicant?

There are many hospitals in my area that offer fellowships/preceptorships/graduate nursing positions. I would like to apply to one when I graduate. The one I would really love to get is in the CICU at one of the children's hospitals in the area. I would be happy with any, but that is my dream.

Due to them being HIGHLY competitive, they are seeking "well rounded" applicants. What can I do to make myself stand out during the application process? Only a handful of the applicant even get interviews so I need to stand out on paper. I know getting good grades and volunteering are important, but what else would you recommend I do?

Thanks for any advice!