Cry yourself out. It oftentimes much better to let out all those feelings which you have bottled up inside through tears. haven't you noticed that after a bout with the sobs, you generally feel better than you did before you cried? Try it, it's a great therapy.
Listen to loud music. Mushy songs are no-nos at this time. loud music - be it hard metal, rock n roll, rap or disco music helps to take out those pent - up feelings in you, especially when you sing or shout along with it.
Exercise. Exerting effort on your body physically may lessen the emotional stress you are currently experiencing. You will be too tired to think of the good old days. Not only will you be able to sleep better at night, you will also be keeping fit. No food binges please...
Keep busy. Bury yourself in work.Perhaps go on overtime. If you are in school, take extra hours in the library. That would leave you with less idle time which permits you to think back about your recent misfortune. The less idle time, the better.
Take out your ex's picture. Then stick it unto your dartboard. No dartboard? Use a cork board instead. Or a bunch of needles and pins will do.
Make a list of your ex's shortcomings. couple it with your own list of what you did to continue your erstwhile relationship despite his inadequacies. Then compare notes. Intentionally make your list longer than his/hers. That sort of getting at him/her already.
Put all the items that remind you of your ex together in a box and keep it in a place where you will not be tempted to open it. Everything must be put away - pressed roses, love letters, pictures...everything. If you keep on wallowing in your past with your former flame, the letting go process will be delayed.
Have a makeover. For the heartbroken females, paint your fingernails fuchsia, change your hairstyle, change your disposition for the better. Make your self more beautiful than ever before. As for those forlorn guys, a great new change in wardrobe will do. Make heads turn.
Go out on a date. Meet people of the opposite sex. Mingle. In a short span of time, you will be back in the social circle again. Who knows? you might just end up getting to know someone new. But warning - no comparing of the former and the current date.
Party.have as much fun as a single person. If ever you encounter your ex in one of those social gatherings, show him/her how much you are enjoying yourself even without him/her in the picture. Greet your ex the way you greet a long lost friend.