White painted stones by Natasha Newton - These would make a nifty place card. Just hand your guests a business card with a matching design on it. Then they get to match the card to the rock at their place. They could then take the rock home as a keepsake.
painted fall foliage on rocks - can't locate a tutorial (site is Chinese?) but I think you could transfer with carbon paper (or pencil rubbed on back of pattern) and trace onto rock, then I would "paint" with sharpie
A circular walk through the Millook woodland reserves to the ancient gnarled oak forest of The Dizzard, returning along the coast with panoramic views to Hartland Point, to the chevron-folded cliffs and honeycomb reefs of Millook Haven.