Formal:
* The old adage "a stitch in time saves nine" holds true in many situations.
* Her grandmother often repeated the adage, "Early to bed and early to rise makes a man healthy, wealthy, and wise."
Informal:
* My dad always says, "You can't judge a book by its cover," but that adage doesn't always apply to people.
* We followed the age-old adage and decided to "strike while the iron is hot."
Figurative:
* The adage "less is more" is often forgotten when it comes to social media.
* The artist lived by the adage, "Art imitates life," using his own experiences to inspire his work.
You can use "adage" to refer to a well-known saying, proverb, or wise saying that has been passed down through generations.