A narration of Ma'qil ibn Yasaar (Radhiallahu Anhu) who narrates that the Prophet (Sallallahu Alaihi wasallam) said:
*"It is better for an iron rod (nail, needle etc) to be driven into the head of a man, than for him to touch a woman who is not permissible for him." *
Great thread. It is the above mentioned hadith that has always helped me control these hand shakes & smiles.
As CB mentioned you tell them politely that its not in your religion. At work I have always had customers who at the end would be like its was nice doing business with you & initiate a hand shake. My thing "Ohhh apologies or no offence but I don't shake hands with men. Its not in my religion." Beleive it or not you get more respect from these gora men. There has been once incident where a guy who was black got really offended & thought that I was avoiding the hand shake because of skin color. Good thing his wife was more understanding. I have also been labeled a lesbian once because of this thing. But who cares at the end I would rather not get gunnah then please someone who I won''t be with in the long run.
Also sometimes people ask me what religion is it or most of the times know its Islam. It actually ends up being healthy conversation where they learn something better about us Muslims then one thing we have been labeled after.
Every woman knows what her way of talking can do to a man. You can still get your work done, get those discounts at stores & still have your dignity.