I also have them do lab exercises and fieldtrips that utilize a hands-on approach. I am never happier than when I am in the field on the rocks with students and colleagues. Important in all teaching is being inspiring and enthusiastic about it. Also, in graduate research one has to be encouraging, caring and thoughtful when guiding a student through a difficult and frustrating part of a research project. For me, many practical problems make the most interesting and intriguing research projects.
Earth science provides an abundance of unique problems.
We are often faced with reconstructing phenomena that took place millions of years ago that are not currently taking place in today's world. It is fascinating and challenging to put together a reasonable interpretation of what happened long ago with the limited data preserved in the rock record.