In a making-of clip exclusive to Express.co.uk (above), the crew open up on the new additions to cast, including Basinger.
The 63-year-old Golden Globe winner played Elena Lincoln in the sequel, and Foley said: “She had a real insight and curiosity about this character.
“Kim was one of the great people to work with.”
Johnson added: “I was so nervous because I’ve admired her work for as long as I can remember.”
Jamie Dornan, meanwhile, provided some context for the character herself, who comes between his alias Christian Grey and Johnson’s Ana Steele.
“Christian feels that he needs Elena. He’s still tied up with her in terms of business,” he said.
“But he’s far too involved with her for Ana’s liking.”
In the same clip above, the stars – as well as author EL James – introduce other franchise newcomers Bella Heathcote and Eric Johnson.
Heathcote plays Leila Williams, one of Christian’s former submissives, while Johnson is Jack Hyde; Anna’s boss.
Fifty Shades Darker performed well at the box office earlier this year, and its follow up – Fifty Shades Freed – is out next year.
Fifty Shades Darker is out now on Blu-ray, DVD and digital download.