WATCH | Enjoy some of the most hilariously awkward debate moments of all time.
While not much is known about how Hillary Clinton and Donald Trump prepared for their first face-to-face debate, we can assume they took a cue from 56 years of presidential debate history.
Mock debates are a mustTypically the candidates will hold mock debates, giving them an opportunity to practice against a stand-in.
Notable stand-ins include Democratic strategist Paul Begala as George W. Bush, Ohio Sen. Rob Portman as Barack Obama and Michigan Governor Jennifer Granholm as Sarah Palin.
Some campaigns even hold "debate camp." Before the first debate four years ago, President Obama holed up in Nevada for three days with John Kerry as his sparring partner.
Use rehearsal to get it off your chestEli Attie, former "West Wing" writer and producer who worked as a speechwriter for Al Gore, says it can be valuable for candidates to use these mock debates as a safe space to vent.
By debate night, it's out of their system.
"I remember Paul [Begala] would almost like to provoke Bill Clinton a little bit in preparing for a press conference so then he would vent and he would blow up in the sessions," Attie said.
You want a good punchy line, but I think now more than ever, there's a real premium in these campaigns on authenticity.
Practice makes perfect. Until it doesn't. Part of these rehearsals involve the candidates fine-tuning their message.
WATCH | Earlier this year, Marco Rubio was mocked for repeating four times the same line of attack during a GOP primary debate.
As Rubio proved, the challenge for many candidates is driving their point home without sounding like a robot.
A bad candidate uses that line over and over again.
"A good candidate, like Bill Clinton at his best or Barack Obama, they find ways to make that point over and over again. A bad candidate uses that line over and over again," Attie said.
WATCH | He was sweaty, his shirt was too big, and after a day of campaigning, he was exhausted. Richard Nixon's poor debate showing against John F. Kennedy went down as one of the worst in history.
Style over substance?
That 1960 debate proved style can matter as much as substance.
"Kennedy did much more of a traditional prep, and obviously we saw the result of that," Alan Schroeder, author of "Presidential Debates: Fifty Years of High-Risk TV," said.
Nixon believed experience alone was all he needed to go head-to-head with the younger Kennedy. Those who watched the debate on TV thought the relaxed and confident Kennedy was the obvious winner.
The day of? Take it easy.
Attie likens the day-of debate prep to an athlete's warmup routine before a big game. Candidates shouldn't overthink it.
"You want to stay warm, you want to be limber, you want to stretch but you don't want to do an exhausting workout."