If you need to ask someone a favor, do that over coffee.

The next time you need a favor, work a cup of coffee into the asking.

 

According to the European Journal of Social Psychology, a dose of caffeine makes most people more flexible and prone to persuasion.  If the person you need a favor from is a man, you might want to ask them via email, after they’ve had their morning coffee. Men are more apt to accommodate a request made in writing, while women prefer you ask face to face.