talk the hind leg off a donkey

all talk and no cider

All talk and no results.

an arm and a leg

Usually used after the verb cost, but also often charge, pay, and spend: a very high price for an item or service; an exorbitant price

big talk

Statements which are boastful or exaggerated.

break a leg

Good luck!; Do your best!; Said to someone wishing they perform well in a theatrical production or comparable endeavor.

coffee talk

Informal conversation among friends or acquaintances, of the kind that occurs in a casual gathering where people sit together and drink coffee.

donkey work

Work that is difficult, boring, and routine.

get a leg up

To get a boost or a lift.

hang a leg

To hesitate; to hang back.