Tips … or just urban legends?
If you want a girl, go with shallow penetration.
If you want a boy, go with deeper penetration.
Shallow penetration, preferably with the missionary position, will deposit the sperm closer to the entrance to the vagina. This area is more acidic than closer to the cervix and acidity will work against the weaker “boy” sperm leaving more “girl” sperm available to fertilize your egg. Source.
If you want a girl, don’t orgasm.
If you want a boy, orgasm.
The body produces substances after orgasm that makes the vaginal environment more alkaline, which favors the “boy” sperm.
The contractions which accompany an orgasm help move the sperm up and into the cervix, giving the “boy” sperm an extra chance at being available when your egg is available for fertilization. Source.
Trying for a boy seems like the better deal, huh?