Once you've created a section on your resume for your related experience, describe your experience. Use paragraph style, bulleted style, or a combination of both . . . What matters is that you demonstrate that you actually learned something. No one expects you to have directed a multi-million dollar project, but anything you can show that lets the reader know you gained some knowledge about your chosen field is good. Then say so.
Employers like to hire people who can work well with others on projects.
Write it down. Don't forget to include these accomplishments. Interview - Don't forget to discuss your related experience in your interview. If, for some reason, the interviewer doesn't bring up the subject, try to bring it up yourself. Keep in mind what work will be involved in the position for which you are interviewing and describe your experience in a way that shows how you might fit into that position.