Somewhat related, instead of signing the back of your credit card write "ASK FOR ID". Many merchants that otherwise wouldn't ask but look at the back instinctiv

Somewhat related, instead of signing the back of your credit card write "ASK FOR ID". Many merchants that otherwise wouldn't ask but look at the back instinctively tend to ask when they see it. I reinforce the behavior by thanking them. The only problem I've encountered is some USPS offices refuse to run a card without a signature on the back.