"You know what they say..." in Japanese


So, I'm living in Japan right now, and I've been stocking up on idioms to make
my speaking a little less stilted. In English, I like to proceed an idiom with
something like "You know what they say," or "We have a saying-" but I can't
find a similar structure in Japanese via googling, and of course Genki isn't
very useful either. Is there something like that in Japanese?




I think you could say:

> (ほら、)よく言うでしょう、～～って。  
>  (ほら、)よく言うだろう、～～って。 (← casual, masculine)  
>  (ほら、)よく言うじゃないですか、～～って。  
>  (ほら、)よく言うじゃない、～～って。(← casual, a bit feminine)  
>  etc...

