Set your profile properly
Use your real name and a picture of yourself, so that other users can easily find you.
Reply to your fellow carpoolers
Be courteous and reply when someone offers you a ride or requests one from you. This way, you can also come to an agreement regarding your meeting time and place.
Being late is often bothersome to fellow carpoolers. It is ok to be a bit behind schedule but, if that happens, simply let your carpooler(s) know.