Perhaps you’re working in a laboratory at your college or traveling to a new institution in a far flung location. In either case, a research internship can be an incredible stepping stone in your professional, intellectual, and personal development. Over the summer, you can learn cutting edge techniques, expand your network, and refine your interests as you look towards graduate school or the job market. The process of obtaining a summer internship can be as long and subjective as applying for or choosing an undergraduate institution. Summer research programs are increasingly competitive—some such as Amgen programs have 1,000 to 2,000 applicants for just 2 dozen spots. The strategies and specifics of acquiring a summer research internship could be a “Ten simple rules” post of its own, so we point readers to articles and tools that have explored this topic previously (S1 Table). Keep in mind that you don’t have to be at a prestigious institution to learn new techniques, gain exposure to a new research field, and connect with scientists and other scientists-in-training. Guidelines have been presented in this article series on how to approach undergraduate research in general [1]. Building on these helpful rules, we observe that summer research internships present unique challenges due to their immersive and time-limited nature. That being said, these short-term positions present a unique set of challenges that may prevent interns from getting the most out of the summer months. For instance, research projects often operate on the timescale of years, leaving it unclear how to best spend an 8 to 10 week internship. With busy summer schedules and unclear expectations, interns may end up completing laboratory procedures without intellectually engaging in their project. To help interns and mentors navigate these and other related issues, we have compiled advice based on our collective 16 summer research experiences. We hope that these suggestions will help interns optimally learn from and contribute to their lab. More broadly, by sharing these tips, we hope more interns will experience the thrills of laboratory research that have led all of us to pursue careers in science. Rule 1: Plan ahead! Any project that you work on as an intern is probably part of an effort that spans multiple years. To have a meaningful internship experience, you need to have a small slice of that project that is both significant and doable in a short amount of time. It is not easy or obvious for your mentors to design a summer project that achieves both of these goals. Planning ahead with your mentor can help make sure the internship experience is productive and engaging. In general, mentors who take on undergraduate summer students want to create great projects, but busy schedules may hinder extensive planning. Postdocs and graduate students may learn that they are expected to advise a summer student with a week or two of notice, and must cobble together suitable projects. As soon as you are accepted to a summer internship, reach out to your PI to express (1) your excitement at working in the lab, (2) that you are eager to begin discussing your project with your direct supervisor, and (3) ask for reading material to gain background for further correspondence. Repeat these sentiments prior to your arrival as well, as a reminder of your upcoming presence. As you work through preliminary readings, connect back with your supervisor with sections that appealed to or challenged you. If you are able to successfully communicate in this way, supervisors can make subtle decisions in experimental animal allocation, surgery timing, and reagent ordering to facilitate a great summer project.