In last year's Conference League decider, Fiorentina lost 2-1 to West Ham United, conceding the winning goal in the 90th minute, and they will look to avoid repeating the errors of that defeat.
"The only thing that's different is that we've already experienced certain things," Italiano told a press conference before Wednesday's final in Athens.
"We have a bit of experience, we carry that with us and tomorrow we have to show it. We can't make any mistakes, we must stay alert and focused.
"Last year we didn't have a good ending, we'll bring that bitterness to make it end differently."
For Fiorentina captain Cristiano Biraghi, last year's final was even more painful, struck by a cup thrown by opposition fans during the game, but the memory of the defeat in Prague is what will drive him and the team in Athens.
"There was general bitterness, ours and those who had come to Prague," Biraghi said.
"We all want to change a result that we didn't deserve last year. Unfortunately we made a few more mistakes than West Ham and we were rightly punished.
"We want revenge and to take this trophy away with us."
Fiorentina have prepared for every eventuality in the game against Olympiacos, with Italiano joking that they had brought padlocks and chains to stop the Greek side's top scorer Ayoub El Kaabi.
They are also ready for a penalty shootout if required.
"We practiced penalties, because it could be a possibility," Italiano said.
"We have a lot of players with the personality to convert them, we progressed through two rounds of the Coppa Italia on penalties, while in the league we missed some."
Whatever it takes, Fiorentina are set to leave everything out on the pitch in order to avoid a repeat of last year.
"Thinking back to Prague, I think of the boys' faces at the final whistle and I wouldn't want to see them again tomorrow," the manager said.
"For us, the interpretation of the game must be as if it were the last of our careers. No one gives us the certainty that we can be in such beautiful stadiums again and, unlike Prague, certain aspects are needed.
"That game hurt us, the whole club and Florence. We will try to turn the situation around."
