Get Your Students Hired
I totally agree with Walter's comments about using your voice to engage students. I am a naturally animated speaker, I've always been told, and that helps me when working online. I only have chatbox and audio as ways to communicate with the students. I do try to use the whiteboard when it is needed, as well, of course, to type in words the students need to see as well as hear, when practicing their work. Each day, I have an inspirational quote and an image correlated to the saying up on the whiteboard when students first arrive. When doable, I like to bring in a website and/or a video clip from the web to illustrate a point. Also, I think calling on individual students regularly to give their input on the mic helps keep the attention span focused.
I agree that addressing students by name whenever possible is very important because it personalizes the classroom, and everyone in the class gets to know each other more easily. Celebrating their strengths and accomplishments and using praise first (always), then giving constructive criticism secondly, is an effective strategy, so that morale stays up.
Last but not least: I think humor is essential when working with students online, as well as maintaining a relaxed but focused manner when discussing course content.