As I worked, I started to feel the piece sliding downhill. I couldn't figure out what was wrong, although I knew it probably had to do with my lazy lack of thumbnailing. I considered giving up, but instead posted the WIP to the Team Awesome Facebook group for feedback. There the ever-amazing Wylie Beckert gave me some extremely helpful tips, and even did a little paintover for me. She pointed out that the composition was suffering from too much centering and empty space, and the dryad's pose needed tweaking.
I implemented her suggestions and felt hope return to my cold, cold heart. From here on the painting went pretty smoothly.
Besides Wylie, I must also give credit to Hendrick ter Brugghen, whose masterful "Flute Player" painting I shamelessly copied for the man's hand positions.