a la buena de Dios

casually; as God wills; without thought or reflection; any old how; without any preparation; haphazardly; at the mercy of the elements; unprotected

“En la tertulia o el teatro escoge su asiento a la buena de Dios, sin caer en la cuenta de que hay luces que achagrinan la piel, turban la armonía del color y de las líneas y echan diez años encima.” — In the social gathering or the theater he chooses his seat at the mercy of God, without taking into consideration that there are lights that will ache his skin, disturb the harmony of color and lines and will add ten years to his appearance.