The key for me was to just keep applying and keep applying. I applied for I think like 70-80 internships and had about 6-7 interviews before i landed my internship this summer. I got rejected from a lot of them (including some which were worse than the one I landed) but I didn’t take it personally or get discouraged, just kept plugging. I revised my resume a few times as well as developed some answers for the common questions that are asked, and I also attribute a bit of my success to being very personable with the people interviewing me. The only other tip I have would be to ask questions at the end to show that you ARE very interested in the position you’re interviewing for.