Yup. Crack open that piggy bank, kiss your $140 or so goodbye, and hit the road.
Just pick the girl based on reviews - there's no point picking the spa unless you're planning on truly showing up at random and seeing whomever's available. If you're gonna do that, I'd strongly recommend HFH. BP in particular is a bad choice to take pot luck at - the variance is enormous.
Even HFH has the odd shitty attendant, however, and all attendants have bad days.
My own favorites these days: Tarah, Lisa or Jessica at HFH, Alana at BP, and Giselle at IT.
On second thought, Alana or Jessica could scare the crap out of you if you're really new!
The other all-stars everyone seems to like are Cameron at HFH (good luck booking a time) and Alexis at IT.
One more bit of advice: don't sweat getting "high mileage" in your first session. It took me like a year to even figure out how "high" a mileage I even wanted in a particular session (it's not always just higher is better), and another year to figure out how to ask whether or not it was available. Usually the answer is what you'd think: if you see a girl every week, she'll eventually become more relaxed. It's like a PetroPoints program, but with cruder oil.