My First Try at Slow Sync Flash - Critiques? Help?

Obviously I have some improvements to make, but still, I was awfully proud of myself for even this level of shot in the slow sync flash mode last night. It was the first time I tried to do anything artsy with the Nikon, and, it was a lot of fun. This isn't about getting better in my job just for the work that I do, but expanding the creativity in my life outside of Army missions. However, this will, inevitably, benefit me on both fronts. So, I might as well enjoy what I do.

As you can see, the shot came from me having the camera in front of me as I spun around to the tune of slow sync flash.

Comments? Critiques? Please feel free. This is how I learn.

QUESTION: Does anyone know how I can better ensure that I am in focus since I can't really be on both sides of the camera simultaneously, to do so?