Usually communication on the Internet starts with e-mails on the forum or in chat, or emails on a Dating site. In any case, at first you will be able to interest a girl how to communicate in writing. So try to follow the General rules of decorum: don't swear, don't be rude, don't write outright vulgarity.
Find out what the girl is interested, what are her Hobbies, favorite movies. If you met on a forum or Dating website, do not be lazy to read the entire profile or the entire profile and not just look at photographs. Say that girl you like, ask questions - all females love to talk about themselves and their Hobbies in life.
If a girl asks to see your photos, publish only the ones where you focus, came out well, and preferably without other girls in the frame, especially her ex. The original images are, the more likely that she's interested in you. Especially appreciated are stories and photos of travel, Pets.
Do gifts. This is possible even in the Internet: virtual flowers, postcards, voice, or reputation for the pictures girls. Attentions nice any faster and she would reciprocate to the one who is brighter, expresses his feelings.