To try to make the best possible impression. There is something inherently puzzling about this expression, which dates from the sixteenth century. What exactly is one’s “best foot,” and why should it signify putting on a good show? Shakespeare made it the better foot (in Titus Andronicus and King John), and Sir Thomas Overby wrote, in 1613 (Characters: A footeman), “His legs are not matches, for he is still setting the best foot forward.” One writer suggests that “best foot” always meant “right foot,” the left being considered unlucky. Whatever the explanation, the metaphor is still current.