When you employ the techniques that I describe here probably the first thing that you will notice is spam. There is a ton of it on CL. The good news is that it's pretty easy to identify if not avoid altogether. While I can't publish all of my best ideas, tips and tricks for meeting the hottest women on the internet I will freely tell anyone who listens how to greatly reduce the amount of spam in their lives because I despise it so much... except when I employ it for my own personal gain. Yes, it's a double standard. Life is full of them. Get used to it.
Always post at least two ads at the same time from the same account. When you get two responses with the same content you will know that it's coming from someone who took no time to actually read your post. That means it's either a bot or someone who is replying to all ads, i.e. a guy working for a porn site or a girl who is desperate. None of which you are interested in.
Include a request for specific information in your ad. If it's a close call as to whether the responder is real, asking them to call you by name, reference something in your ad or simply answer a specific question will make it easy for you to tell if a real person actually read your ad or not.
Set up an auto responder. If you don't want all of your ads to sound the same you can always ask her to answer your questions after she replies. Mine says something along these lines:
Hey there! Thanks for replying. Before I can decide if you are the woman of my dreams or not I need to be absolutely certain that you are real. I'm an optimist so I hope that you are but before I tell you my life story...
You get the idea. You can even include a different email address in your auto responder that you actually use and let it "screen" your responses before you waste any time on junk mail. It's exactly what the spammers do. Beat them at their own game!
Gotta start cooking dinner for a hot Brazilian Babe. I'll be back with more later.