I was in sales for awhile. I also believe that we all have to be "salespeople" in our everyday lives.
There is a book that I really like. It is called, "Winning Without Intimidation" by Bob Burg. Here is a link:
Winning Without Intimidation: The Art of Positive Persuasion It is a short and great read! I highly recommend it. Great for sales people and anyone in general!
People might not remember everything that you say, what you are wearing, how much money you have or don't have, etc. But, they are going to remember how you acted, the way that you treated them and the way that you left them feeling.