For the most part when we recall the details of our day to someone we focus on the negative points.  Someone cut you off, your boss yelled at you, a series of 12 paper cuts on the same finger etc.  What if instead you focus on the good points of your day.  Revolutionary.  At the end of your day think (or talk) about everything good that occured.  Instead of wallowing in your frustration, embrace some happiness/gratefulness.  Realizing that good things are happening to you on a daily basis is a certain way of adding positivity to your life.