When entering World Showcase, we've (group of friends) ALWAYS have to start out going left around the lagoon, toward Mexico. It sort of just happens naturally, somehow. We never talk about it...it just...happens. Then one time we noticed the trend and now make sure we do it every time. It would almost be blasphemy to start off in the other direction!
A frozen margarita from mexico is always a must.
Spaceship Earth is always a must.
Maelstrom is always a must.
Haunted Mansion is a must.
We don't always eat dinner at Epcot, but when we do its usually at Biergarten. When we wanna be cheap, we hit Earl of Sandwich at DTD.
Also, another silly one: after exiting the monorail (either at Epcot or MK, doesn't matter), we always race to see who gets down to ground level FIRST. And this is an unspoken challenge. We always just...do it. We don't run (except when there's literally NOBODY else around), but we walk as fast as we can weaving by other guests (without running into anyone, of course).
The winner has bragging rights....... silly? Yes, we know. But it's a tradition!