According to the Seinfeld episode in 1997, the holiday includes: a Festivus dinner, an aluminum pole instead of a Xmas tree, the "Airing of Grievances" and "Feats of Strength" (where the head of the household selects one person at the Festivus celebration and challenges that person to a wrestling match. Tradition states that Festivus is not over until the head of the household is pinned in a wrestling match)

Credit: Chingy C via YouTube