Experts in the field of positive psychology tell us that we can get as much out of giving kindness as we do out of being shown it by others.
An ongoing campaign exhorts people to 'practice random acts of kindness' and there's a lot to be said for this principle.
Actually it can be fun going through your day finding odd and unexpected ways to be kind to other people.
For instance I always loved the idea of paying a toll on a bridge twice, telling the official that you were covering the charge for the car behind you too. This random person would then be waved through with a 'the guy in front got it for you'.
But it can be as simple as holding a door open for someone, or (on a train) offering them your newspaper after you've read it, or picking up litter in the street and putting it in a bin.
It doesn't have to be much, but to feel good it ought to be as spontaneous as possible.
Why not have a think about this today, then see where you might be able to casually drop an act of kindness into someone's day?
It'll feel good. Promise.