Students are in the classroom for a variety of reasons and have a variety of skill brought to the classroom, along with a variety of fears. We as instructors must work within these confines and be encouraging, but overall we are there to teach the content and help them learn. 

People learn in a variety of ways, it's important to teach in a variety of ways to increase learning in all students. Practice, practice, practice. 

Getting to know the students and them to know each other allows them to be comfortable when leaving the class, and having upfront expectations allows them to know that they have the ability to do well in the class. 

Even experienced teachers get first day nerves. Keeping a checklist of things you need to accomplish or do beforehand is helpful. 

Learning from past instructors (good and bad) to take elements of their learning styles to create my own. Students want to learn, and the goal of the classroom is education, but you're even teaching things like professionalism.