The Mormon jokes from the Malloy twins are remarkably accurate to true-life, making one suspect that there must have been some Mormons involved in the making of these films. In particular, when Turk is speaking with Saul at the beginning of Eleven, he tells Saul that he should "check out Provo. You could do very well for yourself there." This seems like simply making uncomfortable small talk, until you realize what Saul does to make his living—he's an expert con man! Utah is considered by many to be the testing ground for new scams because there are so many well-meaning people to take advantage of, so when Turk was telling Saul to go to Provo, he was being surprisingly astute.
Saul repeatedly displays the signs that he's dealing with chest pain and other discomforts associated with heart attacks and strokes, which leaves viewers concerned that he might not be able to complete his task during the robbery, or that he might really be in distress when he keels over in the security room. But if you watch closely, he also speaks with his phony "Zerga" accent during a conversation with the other thieves, when he has no need to deceive anyone. Saul was never really suffering from physical distress: he was practicing for how "Zerga" would need to expire on cue during the heist!
Specifically, if you pay attention to Saul throughout the entire film you'll notice the first time he has one of these complications is after Rusty leaves after his talk. He started practicing right after Rusty gave him the ticket!
Why did Linus go on the trip to steal the EMP when the group didn’t need him? Because he was watching Danny.
For Ocean's Twelve, the remaining parts of the crew (that haven't been arrested) need to fake a desperate Plan B, and decide to use the Celebrity Paradox plan of Tess Ocean having a strong Celebrity Resemblance to Julia Roberts to have her pretend to be Julia Roberts. What they don't seem to expect was Bruce Willis being in town...or did they? They knew Toulour was monitoring them, so they set themselves up to fail in their attempts to get the egg that they already stole, and fail spectacularly, as part of their con. It wouldn't be too hard to conjecture that they KNEW Bruce Willis was staying at the hotel they booked for "Julia", knowing he would probably recognize her.
Many times through 12, they plainly have the characters tell you their plan, but you don't realize yet.After the crew plan their times for the heist, Rusty states, "10:45, we all get arrested". Danny responds, "You bet." First time through, you would think it's just a dark joke, considering all the hurdles they had so far. Nope. That was the actual plan to sell the "failed" plan A.
Before the heist begins in 13, Rusty shows up at Bank's office as a seismologist, sternly warning Bank about the potential danger of an earthquake, refusing to leave unless Bank creates an evacuation plan. While the visit is ostensibly to plant a camera in his office (disguised as a seismograph), it's more than possible that the group intended for the evacuation plan to be created as well, thus minimizing collateral damage as much as possible (while also ensuring that the guests leave with their winnings rather than spend them).
Mark Kermode pointed out why the "Tess Ocean impersonating Julia Roberts" gag doesn't make sense - how come nobody points out how Danny Ocean looks like George Clooney, or Rusty Ryan looks like Brad Pitt, etc.
