There are five toll bridges in the San Francisco Bay Area. A while back, some people began paying the tolls of the cars immediately behind them. The drivers would drive to the toll window, and pull out their dollar bill, only to be informed, "Your toll has been paid by the car ahead of you." This is an example of a spontaneous, random gift, something given without expectation of or demand for anything in return. You can imagine the impact that tiny gift had on the driver of the car! Perhaps it encouraged him to be a nicer person that day. Often a single act of kindness sets a series of kind acts in motion.
There is no prescription for how to practice random kindness. It comes from the heart. Your gift might be to pick up litter in your neighborhood, make an anonymous contribution to a charity, send some cash in an unmarked envelope to make someone experiencing financial distress breathe a little easier, save an animal by bringing it to an animal rescue agency, or get a volunteer position feeding hungry people at a church or shelter. You may want to do all these things, and more. The point is, giving is fun and it doesn't have to be expensive.
Perhaps the greatest reason to practice random kindness is that it brings great contentment into your life. Each act of kindness rewards you with positive feelings and reminds you of the important aspects of life - service, kindness, and love. If we all do our own part, pretty soon we will live in a nicer world.