But in his other role, as Prince Harry of Wales, the fun-loving uncle might have some more pertinent advice for George's new brother or sister, whose birth is expected by the end of the month.
"He will be in a great position to give advice to Prince George's sibling," says Katie Nicholl, author of Kate: The Future Queen.
That is because both Harry and the second child of his brother Prince William and Kate, the Duchess of Cambridge, will share a unique perspective on life in the Royal Family: the time spent being the so-called spare to an heir who sits in direct line to the throne.
"The second child has all the perks without any of the responsibilities," says Ingrid Seward, editor of Majesty magazine and author of A Century of Royal Children.
Anyone who is in that position is far enough down the line of succession, she adds, "for them to have extremely pleasant lives without too much responsibility for some time to come."
That lack of responsibility could be a double-edged sword, however, setting up the possibility that the younger royal sibling might founder trying to finding a useful role in life. History has served up plenty of secondary royals who have become unfortunate tabloid fodder.
"In recent generations, there have been some difficulties for the spare, the second son, the second daughter to carve out a meaningful life within the Royal Family," says Carolyn Harris, a Toronto-based royal historian and blogger.
Princess Margaret, younger sister to Queen Elizabeth, is often cited as an example.
In another era, Margaret was seen as cultured and glamorous, revelling in a life of 1950s' high society.
"A lot of people admired her," says Ninian Mellamphy, a long-time royal watcher and professor emeritus at Western University in London, Ont.
"But she didn't seem to admire herself very much, so that her life was one I think of almost continuous sadness."
Margaret's personal life was a particular struggle, marked first by her abandoned hopes of marrying the divorced Group Captain Peter Townsend, and followed by her own divorce later from Antony Armstrong-Jones and other affairs.
Prince Andrew, who was in the No. 2 spot for more than two decades, until the birth of William in 1982, has seen his fair share of tabloid headlines, including being dubbed "Air Miles Andy."
More recently, his name was linked to a messy U.S. court case involving allegations of sex with an underage U.S. girl. Buckingham Palace vigorously denied the allegations, and Andrew's name was eventually struck from the case by the presiding judge.
Even Harry has had his low points, which included wearing a swastika armband to a party (he later apologized) and naked billiard exploits in a Las Vegas hotel room.
Not so much controversy
Harry seems to have put such antics behind him, however, and hasn't been the focus of similarly salacious headlines for a while.
"Harry had to get used to playing second fiddle to his brother from the start, but he has successfully carved a niche for himself and made a meaningful role," says Nicholl.
For second sons like Harry, a military or naval career has seemed almost inevitable. And that service has generally stood them in good stead.
Andrew won praise as a helicopter pilot during the Falklands War in the early 1980s. And "Prince Harry has made a success of his role in the military and working with philanthropic organizations for veterans and organizing the Invictus Games," says Harris, noting that he's been well-received in a current military secondment in Australia, which wraps up his active military career.
"But there are concerns about how he will carve out a role from himself after he's no longer on active duty," she says, noting, "in royal history, it's fascinating how many times that the spare actually became the monarch."
No legitimate heirs
Henry VIII, Charles I, George V and George VI (Queen Elizabeth's father) were all second sons. Elizabeth I and Queen Anne were second daughters.
Often, it was illness and unexpected death that created the shift in succession. But there was also childlessness or the lack of a legitimate son or daughter.
"Queen Anne had something like 17 pregnancies and none of her children survived childhood," notes Harris. "Most died in infancy except one son who made it to the age of 11."
Charles II had lots of children outside his marriage, but none with his queen.
While such scenarios haven't cropped up in recent generations, it is less than a century since the abdication of Edward VIII put his younger brother Albert on the throne as George VI in 1936.
Modern medicine should offset some of the potential for sudden shifts in succession, but Harris cautions that risks remain, particularly for royal men who favour risky careers or leisure pursuits.
Prince Charles, the current heir to the throne, skied to safety after an avalanche in Switzerland killed a close friend in 1988.
The fact that so many royal men pursue military careers and risky hobbies, says Harris, means "there is, sadly, potential for there to be sudden changes in the succession as there was in the past."