Many undergraduates use research internships to gain experience for graduate school. Science, technology, engineering, and mathematics (STEM) programs involve heavy research and lab work duties, for which students are often unprepared and lack opportunities for practice. Evidence supports Undergraduate Research Experience (URE) programs' ability to improve retention in STEM, but research has not conclusively identified what students need to do to excel in these programs. This analysis used a multimethod approach to identify and quantify student-to-student peer advice from six cohorts of a summer STEM URE. We identified six themes in the advice from exit surveys: proactively manage time, communicate with your team, motivate yourself, be diligent, have fun, and accommodate changes in lifestyle. Each theme included between three and five subthemes that demonstrated nuance within the larger themes. Navigating the expectations of a URE is a complicated endeavor, but participants who are close to the experience provide rich descriptions to aid adjustment. Developing strategies for time management and team communication are most important, followed by motivation, work ethic, enjoyment, and practical adjustments.