I have co-created and have been the facilitator for these various ceremonies and rituals:
the blessing of a pregnant woman –
where her friends gather to shower her with love and prayers for the developing child;
the “coming of age” of a sixteen year old girl whose family and friends gathered to remind her of her heritage and to pray for her future;
the blessing of wedding anniversaries
and the renewal of marriage vows;
the relinquishing of anger, pain and sorrow.
In each of these I've worked with the persons involved to understand the significance of the event for them so that we can create an appropriate and meaningful ceremony.
In this context “ceremony” might be understood as the totality of the actual event, while “ritual” would refer to the use of a particular action which has sacramental importance.