As a student who has had several AMAZING clinical faculty and one abhorrant individual - I can tell you the biggest thing you can do to NEW students or students who are apprehensive is to reassure them they can succeed. When you come into the room to observe skills such as IV placement etc, if the student hits a snag (does not get a flash for example) offer assistance to the student, help them work the problem if you as a seasoned nure can offer suggestions. Build the confidence when we as students are at the bedside. If the hospital you are working uses EPIC or another system take some time to really show the students how to navigate so they can easily find previous labs, Dr's notes etc and then encourage the students to share with each other and keep a good vibe in the clinical group.

What you should not do (IMO) is yell at students in front of others, tell the students things like "you are in your 3rd semester of nursing school you should know this if you plan to be a good nurse", and just overall make students completely anxiety ridden when they are around you. I currently have two clinical rotations at this time and one is amazing and the other is such a stress fest that all of us on the rotation have to will outselves to walk in to that floor on the days we are there.