Agree fully with 'hold the meeting in a nice place' and suggest extending that idea to build in intentional play because every teacher has stumbled into a great lesson plan while gardening, hiking, cooking, cycling, knitting, etc. The Kelley "Creative Confidence" often comes when we are not fully engaged in the task. Our mind is allowed to wander, create and connect in unexpected ways. Too often PD keeps me on the status quo line, and great PD should work to resist the status quo line.
What if PD could not look like a bunch of people gathering in rooms with caffeine clutched in hand? What if it looked like meeting at an aquarium for observations and then heading, with clutched caffeine, to process the experience ?