Start prenatal vitamins, if you haven't already.
Getting your body healthy is always good, so all that you mentioned are great things to do. Sexual positions for concieving are best if its man on top... less likely any sperm will leak out, and while your partner is ejaculating he needs to get a deep as possible to deposit the most sperm closest to your cervix.
You can also try ovulation predictor kits and taking you BBT to help you determine when you ovulate, thus when you are most fertile.
The BEST book to get is Taking Charge of Your Fertility by Toni Weschler. I got it by the recommendation of someone and it is AWESOME. It tells you all kinds of ways to help boost your fertility... I highly recommend it!
You could also check out this site, it will tell you when you are most likely to ovulate.
American Pregnancy Association : Getting Pregnant: Ovulation Calendar
I would talk to your doctor again, after a year of trying with no luck, most doctors start looking into other options to try and help.
My husband and I have been trying for awhile (I have a 5 yr old from a previous relationship). But we have been doing everything. I am on prenatal vitamins, my husband researched and started taking vitamins to help boost his fertility. He even got an at-home sperm test, and it was fine. We do ovulationg predictor kits, and BBT... and still no luck.
I visited my OB just yesterday. She said although all my blood levels are fine, and everything looks OK, she said it is possible that maybe I am not "super" fertile, and maybe my husband is not "super" fertile... which means us together its going to be very hard to get pregnant.
She did some more blood work, sent me home with an order to get his sperm tested at a lab. She is scheduleing and x-ray test to make sure my tubes are open so the egg can actually get out (which she said the test is also a treatment, because after having the test it actually boosts fertility for a few months). If all the tests come back normal she is starting me on Clomid (a hormone to make me ovulate).
So after a year of trying, I do think your doctor could be doing a bit more.
Good luck.