At some point, you're going to have to talk to your ex. There simply is no way for you to avoid that particularly if you move in the same social circles. You're bound to bump into each other and forced to make small talk. If you want to get your ex back, you have to know the right words to say.
First things first. You have to apologize to your ex and take accountability for your actions that may have led to the breakup. Own up to your mistakes without pointing out that your ex also did something wrong. This is not the time to point fingers over who is more wrong. Admit your mistakes and apologize for them. That is the most mature thing to do, anyway and your ex will appreciate your being adult about the whole thing. This may even lead to a conversation on what has gone wrong and how you can make things better.
Talk about new interests
Later on, when you and your ex are already in speaking terms, it's only normal to catch up on what you have been doing during your time apart. Tell your ex about your new hobbies or new interests. Tell him or her about the promotion that you got or how you broken a major deal. Focusing on things other than love when you talk to your ex will make them see how much you've already changed, and how attractive the new you has become.
It's OK to start dating again
Once you find your ex back on the dating scene, things will get awkward when you bump into each other. Assure your ex by saying that it's easy to understand that he or she is already dating again. Say that it's a good idea to see other people. This will get your ex wondering who you're seeing. Follow through by seeing other people as well.
Tell your ex you still love them
This requires proper timing. At some point, both of you will probably have to think back and talk about how you were when you were still together. At the right time, it would not hurt to say you still love your ex. It would take a load off your shoulders because you have already said your piece. Your ex will also start thinking about the possibility of giving things another try, particularly if he or she still cares about you.