I wish I had the nerve to do this, but I don't and actually I think just saying that seems strange. I know alotof women have been interested in me over the years, but I just cannot make a move. Some women would try to become friends with my sister or a friend of mine just to get close to me, but I never have the nerve to do anything about it. Some I didn't like though.
One thing I know is that if you like a girl or women, you don't say things like "I like you" or write a long letter. They will think you are weird. You can say I like you or I love your later on, but if you start off that way, that looks odd. Here's what you do. I haven't ever gone very far because of anxiety, but a lot of women either flirt with me or I flirt with them. Usually the former, since I am usually too shy and they are attracted to me for some reason. On the rare ocassion that I am not feeling too anxious, I will flirt. The best way to get a girl to know you like her is to forcefully(and I mean stare straight towards their eyes) make eye contact and maintain eye contact. Never be the one that breaks the eye contact either, because women want someone who is dominant and if you break eye contact first, then your chances will go way down. So, try to make eye contact. Hopefully she will make eye contact with you too. If she does and if she then stares at you, that is a good sign. If she smiles, that is a great sign. If she then starts talking to you, that's even better. So, try to make eye contact and as long as she doesn't just ignore you and look to the side(If she quickly looks down instead of just slowly to the side, then I think that usually means she "really" likes) and just act like she is not interested, then you can start talking to her, but don't just say something stupid like "I like you". You need to make a bunch of small talk, like "How's it going or talk about a current event or make a joke or something. If she then talks back and if she laughs at your jokes, then keep talking and if she smiles a lot and talks to you a lot, then ask her out. I know the proper procedure, but I lack the nerve, unfortunately to get past small talk...