Lots of good responses here, but my 2 cents: Work on your writing. Aim for simplicity and clarity. Avoid words like "explicate" when "discuss" works just as well.

Students with strong STEM interests often undervalue good, simple writing. But learning to write is really about learning to communicate. And one of the most important skills for success, especially as a founder, is communication.

I recommend Strunk & White's Elements of Style as a quick guide to most of the things you need to know about writing.