Cervical mucus is most sperm-friendly at the time of ovulation, when it is more alkaline. Prior to ovulation the mucus is more acidic which is not ideal for sperm and only the fittest can survive. Shettles suggested that making the vagina more acidic means the fitter female sperm are more likely to survive and a baby girl is conceived. A more alkaline environment is better for the faster male sperm and a baby boy is conceived. You could try different foods to influence your vaginal PH.
An alkaline douche containing two tablespoons of baking soda to one quart of water should be used to increase the vaginal environment more alkaline which boost the likelihood of producing a male fetus.