Try something this weekend, be extra extra nice to every person you exchange money or goods with.
Being extra nice causes many folks to give you things, including rounding totals in your favor, or spot you a few cents to make the change returned to you “even.”
We use this a lot very successfully for everything from money to free meat (the lady at the local grocery store just loves talking to Val and the girls and always puts extra slices of meat in our stack, plus KJ gets free cookies!).
Remember, every clerk you deal with is a human being too. They probably get shit all day long from folks whom are pissed off about life. Imagine what a treat it is to them to have someone nice. I'm not suggesting you be nice because it is the right thing to do, I'm saying be nice because it pays off.