Well it is rather easy. I'll use this site as an example. If you notice below each poster to the left you'll see # of messages, # of reviews and date joined.
So if you see a glowing but very vague review for a new lady that doesn't seem to have many reviews and the reviewer just joined yesterday and this is their 1st review. Not claiming that the review is fake. We all were that new guy at some point. But you just have to consider that when choosing to see a lady.
Or you see a few reviews for a lady where some of the veteran guys are suggesting her or giving you the scoop on what she is like you should also consider that. Also read the reviews. Was she bad or just not that particular guy's type. Also if you are reading just a few reviews and guys are confirming and these are reviewers who have some cred on this board...well there you good what more do you need?
Sometime you'll need to read between the lines, For example I know of a lady who is fat but gives really great service. Her weight doesn't get in the way and it doesn't bother me at all, more short and chubby. I am not saying you have to accept or see that lady if is that is a deal breaker for you. If other guys confirm this about this lady, and you're seeing other very similar reviews about her, well, what more do you need?
On top of this you also have the ability to ask an open question and/or a PM to the reviewer.
Finally if you have very specific tastes or kinks you can always ask for a specific recommendation. Best to get very specific. Don't post "who is good at an AMP right now? " Here is an extreme example, I like tiny ladies with tatts, under 30, at least a D Cup and she will walk on my back and give me a golden shower.
If you can cross check a lady with some of the sites mentioned above you'll be in good shape. Another example is EPM & others will post a TER #. Very helpful if this is a lady's 1st trip into Philly. I love this site but it is mainly focused on Philly, NYC.
Good luck