Empathy is a natural virtue but when we grow older, it's common failing to make the connection stronger. You will notice sometimes how you feel like 'it's not your duty' or ignore many things. It's because we don't put much effort to improve our level of empathy.
One of the main reasons to feel less empathy is, we became too centric towards our personal life. We don't see things as a whole. And thus we don't feel the need to help, support others. I wouldn't say, we became less humanistic but more ignorant for sure. That's why working on this is way more necessary to keep social bonding, bring happiness in life.
The first and the best thing we can do to improve our level of empathy is by staying connected with people. When you get to know your neighbors, your family members, friends; how they are doing, what they need it will automatically say to you what you need to do. Also, it helps to improve social connections.
But this is not everything. If we don't allow ourselves to be aware of what's happening around we will not find any clue how to be empathic. We need to understand that sitting on the couch, spending time alone doesn't make us empathic. Rather the more we spread help, support, love; the more empathic we will become.
Moreover, being kind to everyone is one of the best things we can practice to be more empathic. I think there is no need to say that you need to be kind to yourself and others. Showing kindness can always help to improve others as well as our life. You don't have to be rich to support others, you can volunteer on any charity program or even helping a stranger can improve your level of empathy.