Be on time. Be corteous. Be respectful to everyone you meet at the institution and department. Be a team player. Don't forget to smile or be nice. Be very willing to work long hours. Ask politely for feedback at least half-way through to give yourself time to make any adjustments. Treat the patients like they are YOUR patients (i.e., think of yourself as an intern). And also--read, Read, READ! 🙂
I'm sure many others can provide more advice too, but I tried to incorporate a lot of the above during my away and I think it helped to make the experience a good one.