The first thing you have to change - this is related to itself. Accept yourself for who you are, make a positive image. Yes, shyness can sometimes interfere. But it can be corrected. You are on the right track and proud.
Second - you need to understand whether you should deal with shyness. And why would you need it. If you do decide to, then relentlessly follow to the target. We must start now, in any case, not postponing.
Try to greet first. However ... Seeing the object of desire, do not run to him across the street to the first to say "Hello." But if the opportunity presents itself, then greet him first. So you and your manifest interest, and do not think that would have more to say in order to maintain a conversation with him.
Sometimes it happens that a man of your dreams begins to feel sorry for you. Do not let him do that. Such words and attitude will lead to the fact that after a while you will feel worthless, deserving only pity. Defend yourself. Show what you can do. Expressly stated that this treatment you very unpleasant.
By meeting with a man prepare in advance. Find out what he is interested in what he likes to say. Read about it the right literature, including fantasies, finally, talk with friends, competent in the matter. During the conversation, as if by accident, get a new theme. "But I read ...".
And remember, for 2-3 days completely get rid of shyness will not succeed. It's hard work, and you need enough time to overcome shyness. But the result is obvious.