The strength of my friend's profile itself as the constant)The most important thing is to talk more about her than yourself.
Become interested in her as a person (actually interested, and not just to get in her pants because we can smell that from a mile away) and you'll find that the rest of it comes together nicely. PS: Don't forget to have some good pictures of yourself that friends take (avoid selfies if possible) as well as an engaging profile yourself.
I can tell you right now "Hi there, how are you" is going to get you absolutely nowhere.
To get a response you must be engaged and ask a question that makes the woman think.
It's important to come off well in your writing (which since you hang out on reddit I'm assuming you're good at or at least working on) your words need to feel personable like you're chatting together rather than writing a letter.