The phrase "advice of a friend" means receiving guidance or suggestions from someone you trust and consider to be a friend.
Sentences with «advice of a friend»
They might have arrived to the dating site by chance, or on advice of their friends, who were successful. (blogs.elenasmodels.com)
I got health insurance policy plan by taking advice of my friend. (policybazaar.com)
Since I usually travel as a single guy I can not offer advice on that subject but I can share advice some of my friends so you can travel the world safely. (mindthetravel.com)