Moisturise. moisturise, moisturisel Particularly in warmer climates. Nothing makes fragrance disappear more quickly than dry skin. Try using a matching body lotion or oil to your fragrance (many have matching products like shower gels as well the more layers of the scent the better!) Aroma molecules evaporate far slower on well-hydrated skin.
Try also spraying the scent into your hair, too, so it wafts around you all day. Hair doesn’t heat up as much as skin, and will absorb the smell more deeply. Do a patch test, first, to ensure the fragrance doesn’t discolour your hair (spray on a tissue to be sure).