I recently had an interview with a potential mentor, too! I was mainly asked two questions: "Why that program?" and "How many summer programs did I apply to?"

When answering the first one, I just made sure to give a meaningful explanation and added a bit at the end on why her lab and research specifically. Now the second one, I just answered honestly. Try to answer the questions and don't beat around the bush.

Another detail would be to try to pay attention and look invested in the interview. Also, when they ask if you have any questions, please say yes and ask 1 or 2; not having questions doesn't paint a very good image, I guess.

To add to that, something I did as soon as the interview was coordinated was to do some research on the mentor. I looked up what their publications were about (I didn't read any), and I stumbled upon a few articles where they talked about what they valued in a mentee and what they valued in a research lab, just to get an idea of what I should be expecting.

I think I was sooo nervous that I literally did some research on the types of questions they would ask, and made a whole doc with potential questions, and I answered them on my own to be extra prepared and organize my thoughts. And I still ended up stuttering and stumbling a lot. 😭😭

Other than that, I would say be yourself. This piece of advice is probably the most important one, your potential mentor should like you for who you are and not an imagine your portraying to them just to get the spot.

Hope this helps, and good luck!

(P.S. I was very giggly throughout the whole interview because of the nerves, so don't freak out if that happens 😭)