trim one's sails, to

Modify one's stand, adapt to circumstances, as in His advisers told him to trim his sails before he alienated voters and bungled the election completely . This metaphoric expression alludes to adjusting a ship's sails to take full advantage of prevailing winds. [Late 1700s]

To modify one’s stand, adapting it to circumstances. Trimming a boat’s sails means simply to adjust them so as to take advantage of current wind conditions. The term was transferred to human affairs by 1800 or so, but may be obsolescent today. Lytton Strachey used it in Elizabeth and Essex (1928): “Burghley, trimming his sails to the changing wind, thought it advisable to take the side of Essex.”