keep the wolf from the door

bang down the door

To present oneself as a strong candidate for a role or achievement, explicitly or implicitly.

close the stable door after the horse has bolted

To attempt to prevent a problem that has already occurred; to design and implement a preventive mechanism that is too late (after the first failure instead of before).

cobbler, keep to your last

One should not criticise matters outside one's field of expertise; one should mind one's business.

cry wolf

To raise a false alarm; to constantly warn others about an imagined threat, thereby failing to get assistance when a real threat appears.

darken a church door

To go to church to attend a service.

darken someone's door

To arrive at someone's residence or location, especially as an unexpected visitor.

don't let the door hit you on the way out

Used as a command to leave in haste, or to indicate that one is glad, or at least unmoved, to see the addressed person leaving.

earn one's keep

To perform satisfactory physical labor or to provide other worthy services in return for remuneration, lodging, or other benefits; to support oneself financially.