Following Hallease's guidance, I was able to refine my talking-head setup. I moved myself and the camera farther from the wall to add more interesting depth. I was able to work mostly with lights I already had, only buying an inexpensive filter to soften a light I already owned. Before taking this course, I thought lighting was the biggest thing keeping my videos from looking professional. Now I understand that it was a combination of harsh lighting and where I set myself withing the setting. 

Before taking this course (iPhone HDR)
After taking this course. (Sony A6700 probably gets some credit)