Every second day should be fine but its really personal preference and make sure your having sex during your fertile period.
Have you tried ovulation strips? They helped me to work out roughly when I was ovulating.
I have used them in the past but haven't for the last couple of cycles cause I haven't had the money to buy them. And I use to know when I ovulated but I had a Laparoscopy done on 4-17 and I am just confused because I had my period before that and then I bled from the 17th to the 24th. But I didn't get my period till 5-23.
I'm guessing that bleeding would have been from the laparoscopy if it wasn't time for your cycle.
I have a 28 day cycle so to get the best chance of conceiving, my partner and I had sex every second day from day 10 to 18. Its not guaranteed but should cover the fertile period.
You could research foods that might help improve your partners sperm count if you think its nescessary or try some vitamins
I am going to BD every other day I started on day 9 and when I am suppose to ovulate I will probably BD that day and the day after. I talked to my dr and he said to BD starting on day 10 and going to day 20 and BDing every other day.