Experience/projects in a programming language (R, Python, Java, etc)
Familiarity with Hadoop. You don't need experience with this but knowing what it is at a high level is a good idea. https://www.youtube.com/watch?v=9s-vSeWej1U
Data cleaning/munging. Always perform exploratory data analysis and investigate things that don't seem right based on your intuition.
Ability to learn on your own. There are so many types of models out there.. you aren't going to know all of them coming out of school.