1
Take responsibility. If you want to re-start your relationship, you’re going to first need to take responsibility for what you may have done wrong the first time around.
Sit down with each other and agree to have a calm, adult conversation about past grievances.
Take responsibility for your own mistakes, and own up to them openly. Don’t try to minimize or deny things you did wrong; instead, show that you recognize what you did wrong and want to avoid similar mistakes in the future. For example, you might say something like, “I know I wasn’t a good listener and that’s my fault. I was too busy worrying about work (or school or whatever) and I didn’t give you the attention you deserved. I’m sorry and I want to change that.”
2
Focus on moving forward. This applies whether you get back together with your ex-girlfriend or not.
If you do succeed in getting back together, don’t dwell on past wrongs or spend time blaming each other for what went wrong. Instead, focus on discussing what each of you needs from the relationship and discuss how to help each other get it. Focus on what you want moving forward rather than on what you did or didn’t do in the past. For example, you might explain, “I felt like you got annoyed with me when I went out with my friends, and I think it might have been because I didn’t let you know about my plans far enough in advance. Is that right?” Then suggest ways of resolving the problem going forward, like agreeing to give at least 5 hours notice before going out on weeknights, etc.
If you don’t succeed in getting back together, don’t obsess over your failures or over what she did to wrong you. Learn what you can from what worked and what didn’t work in the relationship and start to move on.
3
Have a game plan. If the two of you decide to give the relationship another try, have a clear game plan in place to help you move forward.
Determine specifically what each of you needs and wants from the relationship. Ask, “What do you feel like you weren’t getting before?” and “What can we do to help you get that from the relationship?” Similarly, tell her what it is you need--without being accusatory--and figure out how the two of you can help you get that.
Set reasonable expectations with regard to your responsibility for attending to those needs and wants.
Resolve to talk--a lot. Periodically check in with each other about the relationship and your satisfaction levels. Addressing these issues head-on is particularly important for a relationship that comes with prior baggage.