The heart wants what it wants. Even when things didn't work out with a love interest, the heart insists on having feelings for this person. For simplicity of writing, I am going to talk about him, but this applies to either gender–for we all break up, we all hurt and we all break hearts.
If you are trying to get over a crush, an ex-boyfriend or an old lover I recommend that you see him realistically. Don't romanticize him. If he were the one for you then the two of you would be together.
Also, don't hope. I know that hope is that last thing to die, but hoping for him while trying to heal keeps you spinning in place unable to move on. Remember you are trying to get over him.
I suggest, too, that you don't think about him. Prepare for the stream of thoughts about him that will flood your mind by choosing a subject you will think about when you think of him. What long-term projects do you have in mind? Do you have upcoming travel plans? Are you planning any volunteer activities? Choose something to think about ahead of time and when something reminds you of him or a spontaneous thought sneaks in, select another thought.
Along the same lines, I recommend that you don't talk about him. Tell your friends and your family that, in order to heal, the subject of him is off the table. They shouldn't bring it up and, if you do, they should change the subject.
In the meantime, get busy. Idle time is a fertile ground for thinking, hoping, roaming, wandering... Involving yourself in new activities opens you up to new experiences and new people as well, all essential to your healing process.
More importantly, release him with love. Spirit holds you...and holds him. Spirit will sustain you through the process of getting over him. Pray for his happiness and well-being, everyday, and feel the healing of your broken heart begin.