But in an exclusive interview with HELLO! Online, Deborah told us that the water involved was a "horrifying" challenge.
"It was absolutely horrifying for a costume designer, but I just had to figure out how to work with those scenes. We had to produce a tremendous amount of clothing," she told us.
Leonardo DiCaprio and Kate Winslet in Titanic
And Deborah also revealed that a lot of the costumes worn by Kate and Leo were original vintage outfits: "We didn’t want to destroy them, because they were precious items! We had a long prep on that too because we’d been collecting them from all over the world."Her latest film The Amazing Spider-Man 2 was released in the UK on April 16 but Deborah's career began back in the 1980s.
One of her most iconic costumes was Marty McFly in Back to the Future.
"We needed to find an item of clothing that would be unusual in the 1950s, and something that could also encompass a joke", Deborah said about Marty’s life preserver jacket.
"[The director and producer] asked, 'Can you find us something that we could make a joke about it?' We went through a lot of ideas, and finally I came up with that, and a joke that it could be a flight preserver," she added.
"It was nice because everything was working together. It was doing something that I like to do, which is helping to tell the story through the clothes."
Michael J Fox as Marty McFly in Back To The Future
Research is an important part of a costume designer's job, and Deborah told us that she often undertakes months of research pre-production.
On Titanic, Deborah said: "I really threw myself into that time period by looking at every book, every fashion magazine - any magazine really. It was a big magazine period.
"I did a lot of research based on the time’s etiquette, because that dictated what people wore, especially when it came to wealthy and poorer people," Deborah revealed. "I wanted to know what they would wear for specific occasions, and just little details like when they would change outfits, when they would wear gloves and little things like that."
As for Kate Winslet and Leonardo DiCaprio, Deborah admits that the two actors trusted her enough to not get involved in the costume design process.
"A lot of actors trust you, because they know you want to fulfil their character's needs, and you've done the research, especially for period films," Deborah said.
Leonardo DiCaprio and Kate Winslet in Titanic
Deborah became interested in costume design at the age of ten when she began to join her father on trips to the cinema.
This then led to becoming involved in school plays where Deborah would always volunteer to work on the costumes.
When we ask Deborah which film has been her favourite to be involved with, she pauses.
"That's so hard," she laughs. "I could go back to the costumes I designed for E.T. Designing for Kate Winslet in Titanic was hugely gratifying and a lot of fun, because you got to take it so far. Doing the Spider-Man costume was really challenging and new for me. Everything is a learning curve."
Starring Emma Stone and Andrew Garfield, The Amazing Spider-Man 2 brings back Peter Parker and Gwen Stacy in Manhattan, but this time around they're a little older and a little more wary of the world around them.
Emma Stone in The Amazing Spiderman 2
Based on the comic book series, we ask Deborah how difficult, or easy, it is to design costume for a film when characters already have distinctive outfits.
"In terms of the comic books, you pick and choose a little bit, but there are iconic moments for a character that you're building that you have to stick to," Deborah says.
And she also admits that she keeps the first set of Spider-Man films starring Tobey Maguire in mind.
"I try to think about all of them and use them in my research. You want to think about how he dressed in the last film, as in the next one the characters are more grown up. You want to think about where their journey has taken them."
And what about their character progression? "They're a bit more settled in their style and a little bit more confident, which is what I tried to show in their every day clothes. Emma's character [Gwen Stacy] is entering a new phase in her career so I tried to add a little more sophistication to her outfits."
Having worked with numerous famous actors and directors, Deborah won’t be drawn into discussing who her favourite director is, but she has worked with James Cameron on several of his films, including the highest-grossing film of all time, Avatar.
"Avatar was the first time I worked with 3D animation, so that was a big learning curve, because I wasn’t used to working so much in a virtual world. I think when we started it, I was one of the last people to work on the movie because of the process," says Deborah.
Talking about the animation and 3D process, Deborah believes the samples they created helped to give the animation a deeper and broader texture.
And Deborah enthused that "it was really interesting to see the process!"
Deborah will be working on the sequels for Avatar, and also the planned The Amazing Spider-Man 3.
Emma Stone and Andrew Garfield in The Amazing Spiderman 2
Set within a military setting, Deborah worked with military advisors who she said were often difficult to work with.
"The military advisors don't always agree but are very helpful," she said.
Speaking of the research involved in military films, Deborah added, "There's volumes on the internet of every single rule, from how pressed something has to be, to how long something has to be, even to things like where specific buttons have to be!"
Cameron's new project is set and filmed in Hawaii, and Deborah told us that location always influences her designs.
"You get somewhere and suddenly you get all these cultural references you never would have got without actually being there. You get the vibe of the people that live there, and how they dress. So you pick it all up and use it in your costumes", she said.
Deborah Lynn Scott
It's obvious that Deborah is hugely passionate about her career, and when we speak about the films that she wishes she could have worked on, it's also clear that she is particularly interested in period pieces.
"The Wizard of Oz and Gone with the Wind for sure. They're two of my favourite films. There's a movie called The Greatest Story Ever Told about the circus, made in the 40s or something. If I could do a period circus movie that would be my dream come true.
"But the period circus era… if anyone's out there doing it, I'm available!"