Making your ex want you back is not as hard as it seems. Some of the most effective methods may, at first, seem counterproductive. But when you realize that the human mind is a complicated thing, it'll make sense why these tactics are so powerful.
Your first inclination may be to call up your ex or send some text messages so that you stay fresh in their mind. In almost all cases, this is the wrong thing to do. An extremely powerful tactic is to cut off all communication with your ex. Don't call him. Don't text him. Don't send instant messages. If you call and text and make it seem like you really want to get back together, it gives your ex all the power and it makes you seem needy.
If you take this opposite approach, your ex will be surprised or even confused. He won't be sure how to react.
The next thing you want to do is go on with your life. Hang out with your friends and have a good time. Don't sulk and don't wear the sad little puppy face your ex wants to see you wear. Even someone who broke up with you still has an emotional attachment to you and they're expecting, even hoping, that you'll react with sadness and despair.
By moving on with your life, you'll become a more attractive person. This doesn't mean be nasty or cruel; it just means that you shouldn't put your life on hold because your boyfriend (or girlfriend, guys this works for you too!) broke up with you.
Another super powerful tactic is to look your best. Don't overdo the makeup, but put a few extra minutes into getting ready before you go out. Not only will it make you feel more confident, but it will also make your ex notice you if he sees you. This should be subtle. If you go out and wear a mini-skirt, high heels, and makeup, you'll make a statement alright, but it'll likely be the wrong one.
The last tactic is to smile. When you smile, you're more confident, more attractive, and generally more likeable. Smiling is such a simple thing to do, but so many people walk around with a emotionless stare. It'll make you stand out in a positive way, and it will make your ex want you back even more.
These tactics will help you get your ex back if that's what you want. Even if you don't plan on getting back with your ex, they will also increase your confidence and make you feel good about yourself, which are two of the most important things a person can do to make themselves more attractive. And there's certainly nothing wrong with being more attractive!