This is the absolute-best-way of first contacting a girl when online dating that I have come up with. This will engage her in her world and gets a very high response rate. Plus it will give you something interesting to carry on the conversation with in a natural organic way once she does reply.
It's not a routine or script, it's not about commenting on her interests or relating to her, it's about observation.
In the real world, the most natural and smooth way to begin a conversation with a stranger is to make an observation - followed by a comment. If the stranger is receptive, conversation typically follows.
Here is what you do (and note, some girls profiles will be easier then others to use this method of opening, it really depends on what she gives you to work with, if all she gives you are beauty shots... then this won't work very well).
So all you need to do is look at her photos. I mean, really look. Take a minute to look at the details and do not pay attention to her looks! Now, what is the first thing that pops into your mind when you look at one of her photos?
That's it. It's that simple.
If nothing pops into your mind, look at the next photo until something strikes you as comment-worthy. And It's perfectly acceptable to challenge her here, you don't need to say something nice. Tease her if you can. This is the flirting stage.
Observing and making a comment on her photo will put you directly into her reality. You can choose to express interest, by saying something complimentary, or if you don't want to show your interest just yet, just heckle her about something. She will have to wonder if you are actually interested, or just being a jerk.
An example: I saw this one girl hanging off the top of a cliff, looked rather dangerous, so I wrote her and asked... 'Where is your rope???', I only meant to make fun of her but she replied very enthusiastically and told me the story of how she got that perilous shot on vacation and it wasn't at all safe, but she really wanted that picture!
This is a great start, and I could further this conversation with ease. I touched an emotion when I commented on her picture, and she immediately experienced the memory of that moment, and it showed in her reply!
Remember, that girls are emotional creatures, and if you can engage them, emotionally... online, then you are going to be way ahead of the game.