A Couple of Good References
In addition to what has been previously posted, Ian Anderson's "Turning the Tables on Las Vegas" has a chapter titled "How Not to be a Counter". This is the predicessor to "Burning the Tables and can be purchased for pennies on the internet.
Also, Wong's "Blackjack Secrets" contains excellent info on the demographics of a card counter.
The best teacher is naturally experience. My most recent problem was caused by a matchbook from a casino that I played in the previous day. The PC was sharp enough to know that the matchbook casino had an excellent game. This was enough to precipitate a lengthly question and answer session between myself and the PC. I eventually was able to change the subject to the cute young ladies that hang out that casino. I fed him enough B.S. that he finally left me alone. You have to keep on your toes.
Cobbson