If you really want him back, you're facing almost impossible odds if he did the dumping. You up your chances for success, though, by playing it cool and not acting desperate. If, though, you broke his heart, it will be easier to get him back--but remember, you may likely hurt him all over again and you don't want that.
Pick up the phone--with caution. "Fool me once, shame on you; fool me twice, shame on me." Well, let's add, shame on both of you. After all, some volatile sparks were flying between you both--so that means something wasn't right to begin with. If you want a tempestuous relationship when you're 65, then by all means pick up the phone. If this was someone you were attracted to, but who really didn't get you on any level except the physical, rethink dialling his number.
Act as if everything is great. If you did the dumping, you will probably feel guilty so don't overdo the "life is great" pose. But even more, don't assume he is just sitting around waiting for your call. Often someone will get dumped and then turn around and find a more suitable partner. So don't get cocky. When you call, talk about neutral topics such as the weather, the election (well, skip that one), gardening, that sort of thing. Be upbeat without being nauseatingly so.
Inquire as to his availability now, ever-so-subtly. "Hey, remember Megan? She's now back with Tommy. Didn't you meet her sister once?" could illicit a reply such as, "Yeah, now I'm dating Megan's sister and we're double-dating with Tommy." Don't assume, especially if it's been more than a minute and your ex has a beating pulse, that he's been sitting around. Young, old, skinny, fat--we all move on.
Doll it up. If your ex has agreed to get together with you for something as innocuous as say, coffee, then do your best to look like a supermodel. A good hairbrushing and change from those sweat pants is at least in order. If the date is a week or more away, hit the gym or pool.
Behave as if you are old friends, not former lovers (who later became enemies). When he meets you at the cafe you always loved, it will be tempting to run and kiss him full on the mouth. Control yourself. This person is probably very wounded (or perhaps you are the wounded deer here) and you must tread lightly. Going for a hug is usually OK, but then again, a smile and a sweet, tender hello is just fine.
Study your ex during your talk. Most times, you will see all the things that drove you crazy in the first place. Then again, just the opposite may occur. If you are making out by the end of your second Merlot, that's a good sign (or a bad one, depending on your point of view). Then again, jokes aside, refrain from too much heavy petting during or after the initial reunion.
Search your soul after the date. Did he hit the right notes or push all your buttons, you will ask yourself. If the first is true, he was able to read you just as before and bring out the very best in you. Only he knows that your secret love is playing the cello on a cliff overlooking the Pacific Ocean; only he knows that you are deeply insecure about your height, despite having been a model once. But if this person is picking at you with jabs like, "I can't believe your family is still at it!" "Hey, you never did lose that 6.8kg., did you?" or "My mom says you're just incapable of being in love," well then, m-o-v-e on.
Come to terms with the break-up. Ninety per cent of the time, getting back together with an ex is a real mistake--no matter how tempting or popular the notion may be, especially when you are tired or lonely. Just because you are familiar with someone does not mean you feel comfortable in his arms or home. Check your emotions and also your mind. Then follow your gut.
Return to love. That said, if you are in the 10 per cent of the population who is destined to be with your former love, it could be that you've both grown up and really are meant to be together. A good indication of this will be if physical sparks fly within the first 30 minutes of your reunion. And then if you can laugh throughout your date ...well then, you are definitely on to something.