Here you’ll find some articles with suggestions on how to celebrate the festivals. I’ve included the Quarter Days as well as the lesser festivals:

Celebrating Samhainn
Carving Turnips
Samhainn Divination
Celebrating Hogmanay
Celebrating Yule
Celebrating Là Fhèill Brìghde
Making a Dealbh Brìde
Making a Cros Bríde – three-armed (triskele) type
Making a Cros Bríde – interwoven type
Celebrating Bealltainn
Celebrating Midsummer
Celebrating Lùnastal
Celebrating Là Fhèill Mìcheil