One of the interesting things I've noticed as I've delved into the PGM is the stunning parallels some of the rituals have with classical Hellenic domestic worship; at least as much as we know about it. Of course, domestic worship and folk practices varied so much there was no definitive practice that every household followed though there were certain elements that were generally present (lighting incense, offerings, etc).
With this in mind, I can't help but wonder if maybe we, in our rigorous quest for research and reconstruction are removing the very essence of the PGM that makes it such a fascinating, and useful, body of work. It shows the flexibility of the magical systems of this period and how fluid people were with altering ritual- sometimes even on the fly.
In Ancient Magic and Ritual Power, Smith notes how the PGM represents the commercializing of Greco-Egyptian folk magical practices but, in turn, are we "ceremonializing" the material? Attempting to make it more rigid to match the ritual structures many of us are familiar with?
How cool are you with winging it? Are you going for a reconstructionist approach to the workings? We know the PGM is syncretic so are there any "foreign" elements you've brought in?