The first few days after a breakup are some of the most fragile.
All you can think about is "I want to win my girlfriend back!" You're emotionally all over the place and the temptation to pick up the phone and call her can be overwhelming.
I'm about to tell you why you shouldn't.
Essentially, too much contact between you in this delicate early stage is only going to heighten tension and potentially ruin your chances of getting back together.
Give her some time and some space.
Don't worry, she's thinking about you just as much, if not more, than you're thinking about her.
It's important for both of you to have this time alone to sort out your feelings of where things went wrong.
I realize that in some situations, having no contact just isn't feasible.
Maybe you both work together or maybe one of you has kids.
If this is the case you can still minimize rather than eliminate contact altogether.
"But how can I win my girlfriend back if I never talk to her?" After a reasonable amount of time has passed (give it at least a week), write her a letter.
I'm not talking about an email - a real honest-to-god letter.
Dig out a pen and some paper and get some thoughts down.
This will allow you to carefully construct how you feel and what you want to say much more effectively than a phone call or meeting in person.
The next time you find yourself lying wide awake in bed at 3am in the morning thinking "How can I win my girlfriend back?", get up and get writing.
You'll be glad you did and she just might be too.