Her current projects include a new autobiography, Passion For Life, two films, a cameo in TV series Benidorm, a novel, a big secret project and she's due to perform a new version of her one-woman show next year, which husband number five Percy Gibson directs.
He is wonderful to work with, she says. And according to her new autobiography (or illustrated memoir, as she prefers), he's also a wonderful husband.
So what does Collins believe is the key to a happy marriage?
"Giving each other space and being best friends," she states. "Oh, and trying to have separate bathrooms."
Collins is not one for doling out advice, though. And when she wants some herself, she turns to her husband, and occasionally her younger sister, writer Jackie Collins - but only "up to a point".
Family is very important to her. The first chapter of Passion For Life is dedicated to the topic (there's another about her many friends).
Collins's mother was a dance teacher, her father an agent for the likes of Shirley Bassey and The Beatles - though she describes him as unemotional.
"He wanted me to go to secretarial school, find a good husband, have children and lead a nice, proper life."
He told her she'd be washed up by 23 if she became an actress.
"That was rather prevalent then - there was a tremendous amount of ageism with actresses, and I think there still is."
But his comments just made her more determined to succeed, and prove she could make it.
"I feel I've achieved quite an amount in my time," says the actress, writer and mother of three.
Her father did give her one piece of good advice, though: no-one will ever do anything for you, you have to do it yourself.
"He was right there," she says. "I trusted my financial affairs to people who were supposed to be experts during the time of Dynasty, and they badly let me down. I found myself in deep trouble with the tax man."
That's not the only knockback the actress has experienced.
There were her four failed marriages, of course, before she found happiness with Gibson, whom she married in 2002.
She also suffered heartache when daughter Katyana, then aged eight, suffered brain injuries in a car accident.
The actress was also embroiled in a legal battle with publishers Random House.
Somehow, though, she seems to have stayed positive.
"I was born with the optimist gene," she says.
High points have been plentiful. She began working professionally in her teens and was quickly signed to Twentieth Century Fox. Her big Hollywood break came with a role in 1955's Land Of The Pharaohs.
Film and TV roles continued during the 1950s, 60s and 70s, including two films based on novels by her sister - The Stud and The Bitch.
From 1981 to 1989, she played scheming diva Alexis in hit TV show Dynasty, a role which won Collins a Golden Globe.
She's continued working in film and on stage, has written a number of books and now she's even starring in Snickers adverts.
In 1997, Collins was awarded an OBE for her contribution to the arts and charity. She's a big fan of the Queen.
"I think she is the most inspirational woman," she notes.
She also admired Margaret Thatcher's strength of character.
Collins says she is a "huge fan" of Christmas and is looking forward to spending it with her children - Tara and Alexander, whom she had with second husband Anthony Newley, and Katyana, by third husband Ron Kass - and her three grandchildren.
However, it's hard to imagine an 80-year-old, who can still do the splits and pull off a bodycon dress, doing anything "granny-ish".
"I think there's far too much emphasis on age these days," she says. "It's ludicrous. I don't think one should be defined by age. There are people of 50 who look like crones and people of 70 who look brilliant."
Collins is all about glamour, but she's in leggings and a jumper today, as she is "lying about the house" and meeting journalists.
But she is not one for slacking and has no plans to slow down.
"I don't think I'll ever do that. I can't think of anything more horrendous than getting up and the only thing I have to look forward to is watching TV. No, I'll always be doing something.
"You know what they say: You've got to eat life, or life will eat you."
l Passion For Life (Constable), £25.