The Whelan method
One of the most popular methods is Dr. Elizabeth Whelan method. In her method she is saying that the best time to conceive is before and after the ovulation. Further more she is suggesting that you will conceive a boy if you have sex six day prior to ovulation, and a girl if you have sex near the time of your ovulation. The best way to know the right time of ovulation is to monitor your body temperature.
It is believed that if you take certain dietary supplements you might increase your chances of conceiving a girl. The famous one is of course the Lydia Pinkham Herbal Compound. This can create acidic environment that will prevent Y chromosomes to live in side your vagina so there will be more X chromosomes that will swim up to your egg. Also a method of taking calcium and magnesium supplements for some time before conceiving is highly popular with couples.
The Shettles Method
We can say that this one might be the most popular method for conceiving a girl. Dr. Landrum B. Shettles says that in order to have a baby girl you need to do some of the following: have sex everyday from the end of your period till three days prior to ovulation, your sex needs to be in the missionary position to lower the path that sperm must cross and believe it or not he is against women having an orgasm because he believes that this makes alkaline environment in you vagina.
The O+12 method
This method was created by a mother of six sons that wanted a baby girl for a long time. After her second son she started to follow the Shettles method. She gave birth to four more sons following Shettles method and after her sixth son her friend gave birth to a baby girl. She then found out that this baby girl was conceived on the second day after ovulation. Her plan was to test this. What she had in mind was to have sex 12 hours after her ovulation. She easily knew how to determine the time of her ovulation and she did everything as she planned. Needless to say she has conceived a girl.
You have to know that non of these methods guaranties that you will conceive a girl, but they can increase the chances.