Take a day or two to rest and catch up on the energy you lost running to panels and talks and to traveling.
Look at your notes!
Look at the notes you had written up when attending panels and talks. You can organize them by the date you attended the talk, by topic, by who as presenting, or whatever way makes sense to you.
Share your ideas!
Let your classmates and/or instructor know what you learned at the conference! They may find the information interesting and follow up on it on their own time.
Keep in touch!
Keep in touch with people you met at the conference. Use the business cards you collected and send a quick "hello" to your new contacts, reminding them where you met them. This can build into future professional contacts later on down the road.