My first experiences were with guys I found on Craigslist. Here's a few of my ideas... I'm trying to be objective and generalize instead of injecting what I'm looking for but these tips are prob good basics for a beginner to start and figure things out for himself:
-Rule #1 consider any discrepancy a red flag. If something is off or you just get the tiniest bad gut feeling, trust that and move on. There's plenty of other options that will come along. Patience is def a virtue when it comes to CL.
-Before responding to anyone, watch the ads in your area for a week or so to get a feeling for who the multiple post offenders are. You may even be able to start profiling who posts different ads based on sentence structure, punctuation, capitalization, body stats, misspelling "discreet" (a personal pet peeve of mine), and obviously photos. They'll often change up ad wording, age, pics, or other stats by a little just to throw off CL mods and spam filters.
-Download a reverse image search addon for your browser. They scour a database of online images and will tell you if the pic is posted on any other websites even if it has been modified. Right click it on any pic in the ad or those you swap with the ad poster.
-Swap pics but don't send one in your first response. There's too many pic collectors out there who have no intention of meeting up but just want to add to their spank bank.
-In your email include your stats, what turns you on, what you're looking for, what you're not into. Have a couple different body pics to swap on the 2nd email and explain your reason for not sending in first email. Also ask for a couple different pics. If they can only send one they could possibly still be legit but chances are it may just be an old pic with good lighting that they are physically unable to reproduce this year... or decade. Seriously everyone has a camera on his phone now.
-Meet in a public place to feel things out for safety/attraction. I've broken this rule with guys staying at nicer hotels but there's good odds of being disappointed by the pics. Easier to pull the ripcord and bail when you're not on each other's home turf.
-Be decent and tell the truth. You can't expect everyone to be truthful and honest when everything is so anonymous on the internet, but you can make an effort clean up your little corner and expect others to as well. Eventually you'll find what you're looking for without deception by either party.