I have taken both Joel Turners' and Jim Casto's programs, and for me the most important advice both give is the power of letting down. For me, target panic meant a compulsion to release the arrow before I was ready. I still have that compulsion, and probably always will, although not to the disastrous level that I did when I had full blown target panic. I find myself at full draw knowing that I have a sight picture that will result in the arrow hitting 6” to the left of the bullseye, for example, releasing the shot anyway, and seeing it impact in the exact spot I knew it would. That's actually pretty good shooting; too bad they don't give any prizes for that.
Anyway, when I find myself repeatedly doing this, I go back to letting down. If I’m not able to let down or hold for a sufficient time when I actually plan to shoot, I plan in advance to draw and let down shots that I have no intention of shooting. Drawing, holding until I have the sight picture I want, and then letting down helps to put me back in the frame of mind I need to be to actually shoot in a more controlled manner. Sometimes I have to draw and let down every other shot for a while until I beat back that particular bout of target panic.
This is no substitute for going through the whole program, whether it's Joel's or Jim's, but it does seem to help when you fall off the wagon.