(as) common as an old shoe

(as) common as an old shoe

Lacking in manners or refinement. I can't believe he just put his elbows on the dinner table—why, he must be as common as an old shoe!
See also: common, old, shoe
Farlex Dictionary of Idioms.

*common as an old shoe

 and *common as dirt
low class; uncouth. (*Also: as ~.) That ill-mannered girl is just as common as an old shoe. Despite Mamie's efforts to appear to be upper class, most folks considered her common as dirt.
See also: common, old, shoe
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • common as an old shoe
  • common
  • common thread
  • thread
  • the common touch
  • common touch, the
  • in the Common Era
  • as common as muck
  • common as muck
  • common decency