Dogs are like people, they are individuals so there won't be any definite actions that you can take. You know your dog so be mindful to read his signals. You need to be comfortable and as relaxed as possible so that he is too. My dog is pretty sensitive to my mood and if the circumstances are less than ideal he can become more anxious or has troubling mounting which just leads to frustration for both of us.
Also, within reasonable constraints I leave the timing of mating down to him, but of course this is not always possible. But really it isn't complicated, he needs to follow his instincts and you need to remember he can't be expected to understand anything from a human perspective.
Post mating he rarely wants any attention, he usually only wants to cleanup and go off and be alone. I've learned not to bother him.