I'm not married, but I've been doing some research on it, because I'm getting to that age.
Here's the extensive research I've found. Buy yourself a Basal Body Temp Thermometer. Taking your termperature before you even set one foot out of bed is a good idea. Shake down the thermometer before going to bed so even the motion of shaking it down doesn't affect it. As soon as you wake up take your temp. Record it. This may take several cycles(months) to narrow down your BBT. Just before ovulation, your temp rises. It's not detectable on a regular therm. It's only like .4 to .7 of a degree. So a BB therm is important.
I'm trying for a girl, from all the wives tales I've heard to some somewhat scientific methods....here's what I've found.
In general to get pregnant...
1.) Stay in bed with your pelvic region slightly elevated.
2.) Eliminate caffeine from your diet. Caffeine apparently makes it difficult for the egg to implant if it's fertilized. Thins your walls or something. Read too much can't recall exactly.
3.) The man should drink caffeine, apparently it makes the sperm hyperactive.
4.) The man should definitely not smoke, obviously the woman shouldn't either. But when theman smokes it helps to produce defective sperm, so the chances of losing the baby or having a child with problems increases.
These aren't real tried and true, but fun to try if you're hoping for one or the other...
For a boy....
1.) The man should eats lots of red meat.
2.) The man should wear briefs.
3.) Do it "doggy style", deposits the sperm closer to the cervix, and the male carrying sperm are faster swimmers but don't last as long, they are more likely to get to the egg first.
4.) Man should take a hot bath just prior to intercourse.
5.) Have sex at night.
6.) I've heard this two ways, either have sex 3-4 days prior to ovulation, which to me doesn't make sense, because the male carrying sperm would have died by then -OR- Have sex 1 day prior to ovulation up until 1 day after ovulation.
7.) Have sex on odd numbered days.
8.) Douche with baking soda and water prior to sex, the male carriers favor the alkaline environment.
For a girl...
1.) The woman and man should eat lots of veggies.
2.) The man should wear boxers or no underwear.
3.) Do it missionary, with man on top, and woman on top. Either one is further from the cervix.
4.) Woman should not orgasm during sex, or at least prior to the man, something about the orgasm changes the PH level in the vagina, that kills or weakens the female carrying sperm.
5.) Have sex on a full moon, in the afternoon.
6.) Have sex 2-3 days prior to ovulation. The female carrying sperm are suppsoed to be heartier than the male carrying sperm, in that they can live longer, but take longer to get there.
7.) Have sex on even numbered days.
8.) Douche with a vinegar and water douche prior to sex. Apparently the female carriers favors the acidic environment.
Again, these aren't guaranteed, but it'd be fun to try a few of them, if you're leaning one way or another. I'm going to try a few girl making ones, but if I have a boy, then I'll be just as happy.