I try and make it a habit.
People are so stuck in their own mindspace that they can often be worrying about their own issues too much to interact properly with those around us. When I consider it, the only purpose we have here is to interact with the universe around us. It is our choice whether we make it positive or not.
Small acts of kindness do so much for our sense of worth and impact that universe in a positive manner (mostly:) so I try and do that automatically at every opportunity.
That's a good point, people are so caught up in their own lives these days they fail to see that looking beyond actually has great benefit and small acts of kindness or generosity pay big dividends.