Dos and don’ts of getting pregnant after 40.

I spent what most primarily consider their childbearing years married to a man with both children from a previous marriage and a vasectomy. I was ok with the idea that I would never have a child of my own, because his children still do very much fill some of that void for me. That being said, I’m in a committed relationship with the most amazing man, who is willing to accept this, but does truly want us to have one of our own. What are things we should avoid, absolutely do, and consider, if we are to proceed?