Anything other than a breakup in person is just lame, especially if the relationship has lasted a long time. Don't text, Facebook, call or email her to break up. You can say that you want to talk via these methods, but do the actual dumping in person. Letting her know that you want a sit-down will also help her begin to emotionally prepare for the meeting.
Breaking up with someone in public should not usually be done, but it may be necessary with your particular girlfriend, depending on her demeanor. If you think that a private setting will make her needy and clingy, which will ultimately lead to her feeling ashamed of her behavior later, ask her to meet you in public. This way, she will keep her composure and confidence in check.
It is best with most women to have the breakup discussion in private. This helps her to understand the reasons for the breakup and the consequences and gives her the time to ask you questions.
Don't recite a list of her annoying habits. Let her know that you still think that she´s great and a good girlfriend, but you don't see the relationship working out. Comfort her, but stay firm in your stance.
Acknowledge any wrongdoing on your part. If you were unfaithful, come clean. Let her know your part in why the relationship didn't work out. This may not help her at the moment, but she will feel better later to know that the breakup was not entirely her fault.
Don't fight during the breakup discussion, blame her for her mistakes or call her names. Simply state the facts, talk in a calm and collected manner and realize that this information may be devastating to her.
Be honest about why you are breaking up. You don't need to say that you are breaking up because she is clingy and preventing you from seeing more attractive women. Simply state that you and she do not have the same viewpoint on your relationship and where it is heading. If she wants a commitment and you're not ready, tell her.
Let her know that the relationship is over and be sincere. Don't call her later when you feel guilty and try to be friends. Definitely don't call her to hook up so that she settles for only a physical relationship.
Avoid breaking up with her in a way that will embarrass her. Don't make a scene at her place of work or announce the breakup at a party with friends and family present. Let her take the lead on when to inform other people of your breakup. Keep any negative opinions about her to yourself.
Have one breakup discussion and then move on. Don't drag it out. Give her honest and complete information and then leave after a few minutes of comforting her and apologizing. She needs time to heal and your continued presence will only cause her more pain and confusion.