Forgive your partner for things that have happened in the past, and ask for his forgiveness, too. In order for your relationship to work after a breakup, it's important that things in the past are left in the past and that you start with a clean slate. It's not enough to just say you forgive him; make sure you are prepared to move past any issues that have created problems between you.
Analyze the relationship and determine the problems that caused the initial breakup. In order to avoid problems from those issues all over again, you're going to need to understand them. Jealousy, insecurity and lack of attention are just a few issues that are common in relationships. Make a conscious decision to work on problems that could arise again. Discuss this with your partner and ensure that she is willing to also work on those problems.
Enlist the help of a relationship or marriage counselor. If there are issues that need to be worked through, sometimes outside help is required. Go into the counseling wholeheartedly and with the expectation that your relationship will be better than it has ever been.
Nurture your relationship with attention and affection. Small gifts or gestures can go a long way toward making your partner happy and secure in the relationship. Showing your partner a lot of affection can help soothe the wounds of the past and pave a smoother road for the future.
Listen closely to your partner if he voices concerns or worries with certain issues. Make those issues a priority and take the necessary steps to ensure that your partner is comfortable. For instance, if you're a jealous individual, work on trust within your relationship and let your partner know that you do trust him and that you're working on the jealousy that is present in you.