I've got competitive tree felling, log flume riding, and caber tossing. There's archery and boxing/wrestling. There's chess, there's a pie eating competition, even an obstacle course.
That gives me all the mechanics I'm interested in settling the players into immediately - ranged and melee attacks, skill checks, saves, skill challenges, and roleplay - but I need more fun side bits to help set the scene. There's food stalls, a bar, a little gambling, and I'm probably going to have a children's storytime place the players can go and make up wild tales, but what other kinds of flavour do you pepper around your festivals for the players to interact with?
The campaign is Abomination Vaults for anyone with setting specific ideas.
My players always think they know what I have planned, so I often use the reading to kind of throw them for a loop and give myself a challenge to make the reading accurate, but not in an obvious way
One time, the cards lined up to indicate a betrayal was in the works
So my players got very paranoid, questioning everyone they met, always using sense motive to suss out if they were going to get stabbed in the back
The betrayal came in the form of their intelligent ship, which they never even thought to check had a personality, deciding to return to it's ailing former owner during a time when the players wanted to follow a treasure map they found