The girls kick off rehearsals this week for the 32-date arena concert, which starts in Manchester at the end of this month.
Perrie explained how the group have been given a lot of input into their part of the show, saying: "I think the tour will be a bigger production with bigger costumes.
"It’ll be epic and we're just going to enjoy it.”
Jade added: “It’s fair to say the songs we’re going to do on the tour are the ones the public like the best."
The group, who will be headlining the concert ahead of eight of last year's other finalists, let slip they'd be performing both Katy Perry’s ET and Nicki Minaj’s Superbass during their set.
Perrie said: "[For ET] I'd love or us to be on massive strings and flying through the audience."
And Leigh-Anne teased: "Everything will be bigger and more exaggerated, so you’re gonna love the show. It's gonna be wicked."