Buff Einstein unit with a large octabox in my studio, but you could easily put together something similar with a cheap speedlight, an umbrella, and a couple of $20 reflectors. I shoot hundreds of headshots per year using this simple setup. My standard setup consists of a large soft light source to the left or right of the subject, a reflector under the face, and another reflector opposite the main light source.
I do a lot of corporate and actor headshots around Washington, DC, and I wanted to share some of the simple but effective lighting setups that I use over and over, which you can easily copy and use yourself.