I'm not much of a texter but that would be good practice.  Let's say she has 20 emails to sort through.  
First: you want to meet, dates & times (soon) or she'll think you are a time waster.  Hope that gets her to open it.

Inside, high priority things first.  Keep it short.  Use a private email account & let her know it's secure so she can reply.

Save that for the session.

If you want a gal to get in touch with you, then try to make her life less complicated.  Put down the date, time, and length of service.  She'll thank you for that

Has worked for me.

I agree with MrFisher, don't try to get cute over email, certainly not the first contact.

In the message, I state when/where I'd like to meet, for how long, and type of appointment if applicable based on her site (without being vulgar or making it obvious what this is about.)

Next, my verification info and contact info including whether or not text and VM is okay.

Then a little about myself.

In each of these, there's ample opportunity to make it clear you've read her site. (Read the site) Don't ask for an appointment at a time or place she isn't available. Give all the verification info she asks for, or if there's something she asks for that you don't feel comfortable with or don't have, say so and offer an alternative or ask if there's another way. You can usually get an idea from her site about what types of things might matter most to her as far as what to include in a short "tell me about yourself" section. Here, I'll add just a bit of humor without being rambling.

In general, don't say anything that sounds like the two of you may have sex. Be straight forward and to the point. Read it and use spell check before sending.

I don't have a helluva lot of experience, but this is the type of advice I've seen here from the many wise TER denizens and it has worked for me so far.

I'd think you were a tire kicker. One of those emails like, 'Hi, I'm Mike an upscale exec, 6'0" and 220lbs, with a little belly but I work out, fun, easygoing, and passionate. My number is xxx-xxx-xxxx. Text me!!!!!!!'

If you emailed me w/the subject line 'App' I'd think you were trying to sell me some app.  

To me, a good subject is 'Possible Appointment on Friday' or maybe 'Introduction and possible meeting in NYC'

...of the email, when, where and for how long.  Then a brief introduction.  That's it - short and sweet so they know I'm ready to go and not a time waster.  I've done my homework and know what I need to know without going back and forth and asking a million questions.