I can't believe no one brought it up here.
If you do well, especially if you live the high life, how could you have not run into a couple of those? If you don't mind them, no need to read on.
There's probably more guys than gals here, but I think everyone could contribute to making a comprehensive "Gold digger screener", girls and gay people may offer unique insights.
My two cents:
high risk areas: business and top class (and airport lounges), hotels, certain towns...
high risk groups: girls dress in certain ways (don't have the vocab, but you know what I'm talking about), girls who keep certain company...
preventive measures: find out if a girl has something going for her (those who work certain professions such as doctors, teachers, etc...), some more intrinsic qualities such as compassion, intellect ... if she's ok with being just a f-buddy. Also maybe projection of certain energy when you are about to have sex for the first time with a non gold digger.
I personally don't even own a car, keep two places (nice Zen like one deep in the sticks, crappier one also Spartan has nothing of value in a ok neighborhood, any self respecting burglar would regret ever breaking into it), dress anything female friends don't comment as atrocious. So to me it's not a huge problem, however some good ones can still smell it. One just asked me outright if I'm rich, my answer was "your honesty is refreshing".
ps: I suspect most of us are fairly unemotional and ruthless. If you are, have you noticed that you have a tendency to attract overly sentimental girls who want to "covert" you?