I did not write this and I do not claim ownership. Source is The Black Mountain Druid Order public lesson, which is no longer together unfortunately.
Many ancient Celtic sites are on a hill or an elevated place. Access to these places is often arranged so that the sacred space slowly comes into view as a person walks up the trail. Many modern Druid rituals begin with a processional to the circle. As the group walks to the sacred space, chants or songs are often sung. The march to the circle reminds the seeker that he or she is leaving the world behind and entering into a timeless place. The time spent walking during the processional should be used to leave the cares of the world behind and to bring oneself mentally into ritual space.
Most circles have some sort of gate where attendees enter. This gate can be as simple as two stones on the ground, or as elaborate as you wish. The facilitator of the ritual stands at the outside of the gate, purifying each attendee before they enter the circle. This can be done by smudging, or by sprinkling blessed water on the attendee, or by brushing them lightly with an herb or plant sacred to the occasion, or by simply waving a Bell Branch over them. Once they have been purified, they are free to enter the circle, usually in a clockwise (deosil pronounced jostle) direction.
Here the facilitator briefly states the purpose of the ritual, the significance of the holiday, and its spiritual meaning. A blessing may be asked of the God or Goddess associated with the High Day.
Grounding and Centering
After the Invocation, a brief meditative music piece may be played so that attendees may ground and center themselves, or a brief meditation guided by the facilitator can achieve the same result.
Grounding is a process by which we cease to rely solely on our own energy, and instead draw energy from the Earth herself. To ground, picture yourself as a tree. Roots of energy shoot out from your feet, reaching into the Earth and drawing energy. Also visualize branches of energy from the top of your head, like tree branches, reaching up to draw energy from the sky.
Centering involves becoming present in the moment. Ritual space is a timeless space. Think for a moment about the things that cause you worry and stress. How many of those things have to do with past events? How many of those things have to do with events that have not yet happened, or may not ever happen? Centering is the process of setting aside thoughts and worries about the past and future. When you center yourself, you let go of time and step into a timeless place where all things are possible. It is the process of drawing your attention to nothing but the ritual at hand. Bring all of your attention to the present moment. When you have done so, you are centered.
Calling the Quarters
Some Druidic traditions call the Quarters, and some do not. If you choose to do so, turn and face each direction, starting with the East, and call upon the Spirits or Guardians associated with each direction. The facilitator should stand to the North while calling the Quarters. Use the associations below, if desired, when calling the Quarters. Proceed from the East in a clockwise direction until all the Quarters have been called:
Quarter Element Color Power
East Air Yellow Birth/Creativity
South Fire Red Transformation
West Water Blue Introspection
North Earth Green Stability/Prosperity
The Blessing of Peace
While calling the Quarters, most Druid traditions include a wish for peace. This is usually stated while facing each direction, after calling that particular Quarter. A simple statement such as, May there be peace in the East, should suffice. Be sure to include a peace for all four cardinal directions. Some traditions include a blessing of peace for the Center by simply saying, May there be peace in the Center.
Setting the Center
In many traditions, the Sacred Center consists of the triad of Well, Fire, and Tree. These can be symbolized by a cup or bowl of water for the Well, a candle for the Fire (or an open bonfire if the location and occasion warrant), and a staff for the Tree of Life. The Well and the Fire represent introspection and transformation, while the Tree of Life represents balance, uniting Chaos and Order in Middle Earth. The Trees roots go deep into the Earth, drinking the waters of Chaos, while its branches reach into Heaven, soaking up the rays of the Suns life-giving Order.
Opening the Gate
Once the Sacred Center has been established, the Gate to the Otherworld should be opened by calling upon the Gatekeeper. By opening the Gates to the Otherworld, we allow the wisdom of the Ancestors into the circle.
Offerings (Sometimes called Sacrifices)
At this portion of the ritual, a gift of some sort is given to the Gods/Goddesses of the occasion. This can be a food item tossed into the Sacred Fire, or a libation poured onto the ground or into a bowl. The idea behind sacrifice instead of offering is that you are giving something that means a great deal to you. This is seen in the spirit of only giving your best to the Gods and Goddesses. In ancient times, finely-crafted cauldrons, weapons and such were tossed into rivers as an offering to the Goddess Danu. The offering should include an acknowledgement of the God or Goddess for whom the offering is intended, where appropriate.
Blessings and Concerns
At this point, each attendee at the circle is given an opportunity to express gratitude for any blessings they may have received since the last circle, or to express a concern or problem that they would like help with. This can also be a time for a seasonal expression. For example, at Samhain, members might offer a remembrance of a lost loved one, or at Beltane they may like to share how they have been blessed by a beloved partner. You may find it helpful to experiment with variations on this theme, appropriate to the particular holiday being celebrated. One of the reasons for offering blessings and concerns is that it builds a stronger Grove by allowing each member the support of all.
Reading the Omens
This is an optional portion of a Druid ritual. If there is a question or a concern requiring divination, omens are read by the Celebrant. The method used is up to the Groves personal preferences. Many use rune sticks or Ogham. Some use dice, or some just interpret signs given by Nature herself. I was at a ritual once where a raven landed in the middle of the circle during the Omens. This was especially significant, since the rite being celebrated at that time was in honor of the Goddess, the Mórrígan. The animal most closely associated with the Mórrígan is the raven.
At this portion of the ritual, something specific to the High Day being celebrated is inserted. For example, you may choose to insert an Ancestor Vigil here for Samhain, or a Hanging of the Bells for Beltane, or a lighting of the Yule log for Winter Solstice.
During this portion of the rite, an offering of thanks to the Gods, Goddesses, Elementals, etc. is offered. You may also choose to thank any participants who contributed to the ritual by offering time and/or talents. At our Alban Elved/Mabon celebrations, we usually go around the circle and have everyone name at least one thing they are thankful for.
Closing the Gates/Dismissing the Quarters
At this point, call upon the Gatekeeper to seal the way to the Otherworld. If you have called the Quarters, dismiss them as well. You may also choose to sing or chant a closing musical offering at this time.
Closing the Rite
At this point, you may sing a final song and make any final announcements. We usually end with a Recessional in which we leave the circle through the Gate while singing or chanting. When leaving the circle, go counter-clockwise, or widdershins, around the circle before exiting at the Gate. When the Recessional has reached a predetermined destination, you may wish to offer a thanks or statement of dismissal.
The above outline is just a suggested format for those with little or no experience in crafting rituals. It is by no means a definitive Druid ritual.