hi all.. there are many saying.. one of my friend told me that this is a family past down secret to have a BOY.. she said after your period clear, you have sex on the 1st, 3rd, 5th, 7th.... etc. i dunno how reliable is that but her brother did have a son on the first go.
the more scientific way is that the Y sperm swim faster but they won't survive as long as the X sperm. On the other hand the X sperm swim much slower but they can survive much longer in your uterus, up to 4 days. So the way to go is to have sex on your ovulation day, and not to have sex a few days before you ovulates. There are ovulation kits to check when is your ovulation day or you can simply check your body temperature, the day you ovulation, if i remember correctly, your temperature is slighty higher.
there are actually scientific prove that suggest sperm prefer an alkaline environment, so eating alkaline food could help.
i did my research on it when i was trying to get pregnant, but i found out I AM ALREADY pregnant before i could actually test it out. And i just found out last week that I AM going to have a BOY. but i would be as happy if it was a girl.. cos i want my next one to be a girl.
good luck