S**t or get off the pot, means do something!
All hat and no cattle, means not being able to back up your claim, a liar.
Running with the dry cows, from my grandparents generation means, staying out all night. Cows that need to be milked come home to the barn each night.
Head for the barn, means go home.
I worked with an Englishman in the late 70's and he had a very hard time understanding my idioms.