Keep if brief (but not too short), have fun, make some reference to her profile content, and avoid commenting on her appearance unless there's something you can playfully tease her about -- but be sure any such comments actually are funny & playful, or you'll just look like a dumbass.
And, most importantly, come up with as eye-catching a subject line (and profile headline) as possible. Something that entices them to proceed further. Hot gals can literally get dozens of emails in one day, and often won't look past the subject line and profile snippet.
Here are a few examples of messages I sent that got me a reply:
First, to a gal who described herself as a "geek" in her profile, and described an rather wicked prank some college friends played on her in her profile:
Greetings, geeky one...
Your profile got me a good chuckle or three, so my typing finger just couldn't sit idly.
That campus safety story ... Geez, it's reassuring to know you have such great friends. Dunno if I have it in me to dish out that kind of abuse, but I'm all about personal growth...
Ciao for now,
Realname
Another one was to gal who said she wanted to "find a man who understands women," and hinted that involves "not being able to explain their actions" (Now, how could I resist running with that?):
That's a tall order
... trying to find a man who understands women. You are indeed trying to find a needle in a haystack. Chalk up points for truth in advertising. If you do find him, I'd like to have a chat with the fellow. Before I kill him.
Just kidding. I get the inability to explain some of the stuff you do, but does that constitute understanding? Now that's an interesting philosophical question.
Anyhow, a Catholic gal who enjoys beat literature and has a screen name to match can't be all bad. At least not in a bad way.
I won't hold your fondness for mechanical pencils against you. I do value compromise too.
Ciao for now,
Realname
One younger woman (whose age range was lower than my age, but otherwise she looked like a good match, and said she really likes humor) replied to a message that opened with this:
I know our age ranges don't match, but you look youthful and hip enough that you would not look like you could be my mother if we went out, so I decided to write anyway...
