Your mouth is dry; your voice is shaking. Your hands are clammy and your skin feels, well, prickly, like bees are swarming in there or fruit with spines is falling all over you. You want to talk to him/her but you are just too freaked out. There has GOT to be a better way.
As old as it is, the fight-or-flight response that causes our adrenaline rush when we're going to approach someone we like, like LIKE-like is not dissimilar to how we feel when going into battle. Internet, phone and texting have taken some of the edge off, making approaches more anonymous, less confrontational, but still; there are moments when talking with or to someone you really like should and can be done in person and, in those cases, how can we actually do it and feel good, less shaky, more happy and excited about it?
First, remember that life is an adventure. Nothing is gained by hiding and avoiding the uncomfortable feelings and hiding away from possible connections. Second, think of yourself, your heart, as a country and your approach as the ambassador to this country. You want to be vulnerable in your relationship, but, as you approach, you don't have to be as vulnerable as you really are. You are representing yourself, not giving your heart completely in the first few moments.
Speak as if you were the protector, representative and owner of your country and are happily looking for another country to expand your territory amicably. You don't want to colonize another country, dominating and taking over as a tyrant, but neither do we want to be absorbed without a fight - there doesn't have to be a fight, but rather a peaceful convergence of resources and good feeling.
Granted, chemistry and compatibility are not measurable as political science but representing yourself as a valuable and rich territory can take some of the discomfort out of your approach.
Friendliness, openness, honesty and an easy going sense of really liking yourself will go far in attracting potential partners, but it will also calm you down so that you can regain your center, feel good as you approach and, possibly make wiser decisions about who it is you choose to accept for expansion.