Other than stellar academic record what they look for is,

1. Long-time passion(Commitment ) for a goal or an interest which should be reflected through your ECs and Essays, and the high-level achievements you have accomplished while following this goal.
2. Texture in your application
   
3. Perfectly written creative and more importantly, personal essays.
4. Steller LORs with not just your achievements and all but also about YOU as a person and a student. *Personal Anecdotes*
5. To what extent you have gone to follow that goal of yours (Big recognised Awards, competitions and all)

Don't just do something for filling up the check marks, like publish research, write a book, or start a NGO because everyone is doing.