Here is a bit that I’ve developed over these first few years with ADF, and I find myself unable to comfortably end a ritual without these lines.
After the rite is ended, I blow out any candles (usually just the pillar candle I use for the sacred fire), saying:
Though this fire is here extinguished, may it burn ever on within me.
Then I take the offerings and the bowl of water representing the well (filled afresh before each new ritual) outside and pour it onto the ground, saying:
I return this to the earth, as all things return to the earth.