There is a lot of interesting information at the link about all sorts of Gaelic rituals, but since Lughnasadh is almost upon us, I thought I would highlight this portion:
Lá Lúnasa (Lúghnasadh) / Lùnastal / Laa Luanys — 1 August
In Ireland: Picking the first fruits – bilberries being traditional; horses purified by being driven through water; ritualized faction-fighting between males; boys giving girls garlands of flowers; decorating the hearth with flowers.In Scotland: Cutting of the first sheaf at sunrise while turning sunwise and chanting the iolach buana (reaping paean); making protective charms of rowan and red thread; saining (performing a protective warding) the house and those in it; ritualized faction-fighting between males; garland making; decorating the home with seasonal flowers.In Isle of Man: Visiting high hills or sacred wells; a young woman reaper would ceremonially cut the last corn and bind it with wild flowers and ribbon into a babban ny mhellea (harvest baby); rush-plaiting.