Don’t be so quick to return phone calls, emails and/or texts. Don’t ask him for a status report on his feelings or the situation between you two. Keep conversations light, fun and short. Be busy and happy when you speak to him. In essence, the same things you did to attract him in the beginning are the same things you must now do to “re-attract” him.
If he starts to show signs of wanting to get back together, don’t be so quick to take him back. He’s already bailed once. He needs to prove that he’s in it for the long haul and is seriously considering marriage.