Just consider how you feel after you deal with a friendly cashier at a store versus the cashier that seems annoyed that you have the nerve to interupt her daydreaming. This can potentially spark a chain reaction. If you just dealt with someone who is very friendly, you are more likely to pass it on to the next person you meet. If you just dealt with a very grumpy person you may be more likely to pass that on as well. When you do come across those people that aren't in the best of moods, be sure not to let them bring you down and make a conscious effort to pass on kindness instead of misery.
How will you spread kindness today?