Method 1: Go by the number of reviews for someone who matches your preferences. TERB can be prone to fads, but usually multiple good and recent reviews for someone you're interested in is a good sign.Fair enough.
By the way, does anyone have any tips on how to find the most highly regarded girls from a given agency?
Method 2: Talk to the booker. A booker will always try to get you in to see someone, but they will usually try to line you up with what they consider to be the option that most matches your preferences.
For me I usually look at who's available when I'm available, take note of who I find interesting, check for reviews (though I don't mind no / few reviews when dealing with a reputable agency), and then I'll give a short list of who I'm looking at, and my preferences, to the booker. I've usually had that work out well.