Use a sharp knife to cut a slice off the top and bottom of each of the oranges, then remove the peel and pith, careful to retain the shape of the oranges.
Hold oranges on their side and cut horizontally into slices.
Place oranges in a nonmetallic bowl. Cut the lime in half and squeeze over the oranges. Sprinkle with the tequila and liqueur then sprinkle over the brown sugar to taste (two tablespoons or so should be plenty).
Cover and chill till ready to serve, then transfer to a serving dish, mix gently with the berries and decorate with lime zest. Enjoy!