Ferguson celebrates an incredible 25 years as Manchester United manager on Sunday.
Giggs has been part of the Scot's plans for all but the first five, becoming an integral part of 12 titles and two Champions League triumphs, the pinnacle of Ferguson's stellar career.
Yet, approaching his 70th birthday, Ferguson still pursues a relentless schedule, showing he is capable of following his own advice.
"You can have all the qualities in the world, but hard work is the key to everything," Giggs told Inside United.
"He's seen plenty of quality players come and go at United over the years, but the main thing that sets great players apart from the rest is their work ethic.
"And he leads by example, of course. He's always first in at the training ground and last to leave, and he wants to see that kind of mentality from his players as well.
"He just loves his job. He loves watching United play. He loves seeing players develop. He loves everything about his job. You couldn't do what he does at his age and have the work ethic he's got if you didn't love it.
"We might have got home from a European away game at four in the morning, yet you can pretty much guarantee he'll be first in at Carrington at 8am the next day - and will be last to leave.
"You'll then stick the TV on later that night and see him at a function in London. It's unbelievable."
It is hardly a surprise therefore Giggs cites Ferguson as having the greatest influence on a playing career that has seen the Welshman amass more medals than anyone in English history.
"I have known him for 25 years now and he's seen me develop from a 13-year-old to where I am now," said Giggs.
"He has always been there to support me and help me develop my game.
"And he's always known what's best for me during my career, especially early on, and now at this later stage too."