My husband and I tried to conceive for about 3 years and then we had testing done to see if there was a problem. It turned out that my husband has a low sperm count and poor motility. We ended up going to see a fertility specialist to discuss our options. He gave us only a 7% chance of conceiving using artificial insemination, but a 70% chance of conceiving thru IVF. So we did 2 cycles of IVF and ended up having a beautiful baby boy (2 1/2 years ago now). We never used protection since the chances of us conceiving were slim to none especially on our own and low and behold, I am currently 8 weeks pregnant, so anything can happen.
The one thing that all of the doctors stressed as far as lifestyle goes (and was for both of us or some just for hubby) was No Drugs (any kind, unless emergent or for a chronic problem etc...), No Caffeine, No Alcohol and taking vitamins. We got my husband about 4 different things that a urologist told him to take (I believe it's the same list of vitamins for prostate health plus a multivitamin). They also told us since the problem was my husband, they wanted him for 1 month prior to coming in for the procedure to adhere to the above guidelines and make sure to ejaculate regularly. They said that they wanted him to have a "fresh" supply of swimmers "not junky old sperm" as they put it. Not sure if any of this will help you, but it's worth a shot.
I've also heard that taking Robitussin (female) thins out the cervical mucus so that it's easier for the sperm to get through it up to the egg. Again, not sure if it works, but they are all pretty benign things to do that may help. I also used ovulation predictor kits. At least they pinpointed the most fertile days to optimize our chances.
Good luck.