Tips for mentors
It is very helpful to establish your expectations up front. This is more difficult to do than it sounds, so it may take some time before you are able to fully articulate all your expectations. The more you take notes on this process, the smoother it gets as time goes on.
Prepare in advance for typical undergraduate student "crunch" times, such as midterms and finals, and do your best to plan with them for how you will both predict and navigate these waters.
Learn about fundamental attribution error, which means that people have a tendency to attribute other people's behavior to internal factors (factors about the person) and our own behavior to external factors (factors about our situation). If you can teach this to your students as well, that will help you both understand your natural tendency to attribute behavior such as not responding to an email to factors about the student (e.g., the student is lazy) as opposed to the situation (e.g., the student has had the flu). Ask your students to be sure to provide any relevant updates on their situations as soon as possible, so you can continue to plan.
When appropriate, send your student to resources on campus to get help completing their project. Here are some great resources to consider: