Never characterize the importance of a statement in advance.

Never eat prunes when you're hungry.

Never say, "Sorry, we don't have what you're looking for." Always say, "I just sold the last one the other day."

Never use one word when twelve will suffice.

Never hold a rap contest at a square dance. 

Never buy a recording of a heavy metal barbershop quartet.

Never listen to Chubby Checker's "Let's do the Twist", when you're stuck in quicksand.

Never be the first to do anything.

Never let go of what you have unless you have hold of something else.

Never put off until tomorrow what you can put off until the day after tomorrow.