I think a post the other day from John Michael Greer gives us something to work from.
"Basically, as I see it -- and it's very much a personal perception, not
something about which dogmatism is appropriate -- the central principles
of Druidry (as the Druid Revival reinvented it, of course) are reverence
for nature, respect for the individual, and participation in the Druid
tradition. There are any number of changes that can be rung on that, but
by and large a Druid nowadays is somebody who experiences the sacred in
or through nature; who claims the right to make up his or her mind about
the issues that matter, and grants that same freedom to others; and who
finds some things in the 300-year accumulation of hardware that is the
Druid Revival tradition useful in his or her spirituality."
So the essentials are, appropriately enough, another Triad, characteristic of Druidry:
1. Reverence for nature and the experience of the sacred in nature, with a resulting nature-based spirituality.
2. Respect for the individual, and that individual's free will and right to make up one's own mind. This is fundamental to the inherent sovereignty of the individual. This is most appropriate for Druidry, as the ancient Druids of the Celts led the fight for independence and sovereignty of their people, nations, and cultures against imperial Rome. The implication for today is a corollary that each individual has this inherent free will/sovereignty, which provides a basis for mutual respect.
3. Participation and engagement with the Druid tradition, however one defines it. This last element could provide some dissonances between some people whose view of and definition of Druidry is different, but as long as #1 and #2 above are in place and are foundational values, people should be able to find their way through it :-)
In fact, I would say that an approach based on #1 and #2 would be appealing to many, many folks, besides self-identified Druids, and could be the most inclusive and workable approach to fostering dialogue: "Nature, Spirituality, and Sovereignty." Buddhists, Native Americans, many Christians, Conservationists, people interested in natural history, various pagans and people of goodwill, could join with Druids in such a dialogue and share traditions in gatherings, workshops, talks, and common actions...not necessarily ritual as such, perhaps planting trees or cleaning a stream...something related to care for nature and for each other as sovereign individuals.
This triad is something many people, otherwise not into religions, or even hostile to weird things like Druidry, seem to be able to accept and take hold of....as many say "Well, if that's what Druids believe, then I must be a Druid..."
That's how I came to regard myself as somehow a Druid as a little kid back in the late 60s. I already had my identity as an traditional Native American, but what about all my European blood and my European ancestors, and the parts of my love for nature that were not part of my Native American traditions? How to understand and label that stirring I felt when looking at megalithic monuments, at the pagan architectural roots of cathedrals, of my love for ancient trees as elders...the Druids came closest to putting a label on that deep emotional identity. I did not know anyone could be a Druid anymore, but I decided that somehow, that must be what I was.