The only thing I believe that can really boost up your chances it timing ovulation. I don't believe in diets herbs and all the rest.
I had 3 boys 21 19 and 12 when I got pregnant by accident with My Ava Sofia (I lost her at 22 weeks) but I know for a fact she was conceived 3 days before my ovulation , this is fact.
I didn't eat different or do anything different. My SIL also has 3 boys and it took her about 7 months to get pregnant cause she always did it 3 to 4 days before her ovulation, when you do it 3 to 4 days before ovulation it does take a bit longer for some to get pregnant. 9-months later she had her girl . Do I think it is 100% no but it does IMO boost your chances a lot.
People think it is 50-50 for gender ,really it is not, it is 49-51 more boys are born than girls. I know some believe in diet and position of sex, I don't . For me it is all about timing, I don't think it is a coincidence that both my SIL and I had girls, for me it was accidental the 3 days before I ovulated for her it wasn't. She bought OPK's watched her ovulation for months, didn't change her diet or anything and the timing gave her, her girl..
Again this is just my opinion, wish all of you the best of luck.
They say for a boy the day before ovulation the day of and even the day after and this was true for me with all my 3 boys, didn't know about the girl theory back then..
All The Best