This post has been done loads recently,
have a look around at some of the other
posts.
You need a healthy balanced diet, try
folic acid supplements, and have a good
sex life.
Every other day is better because it
allows your partner to build his sperm
reserves back up.
Unless you have a far out cycle try having
good sex every other day from like day 7/8
(day 1 being first day of period).
If you don't feel like sex on a particular
day then don't do it.
The key is to not try too hard. Just
enjoy the trying
