The premise to this ideology, founded by Donald O. Clifton, PhD, is that everyone carries around an invisible "bucket" with them all day. You can either "fill" buckets by doing and saying nice things, or you can "dip" into buckets by doing or saying unkind things.

Having this type of "visual" for children helps them to understand that what we say and do can effect the happiness of others.
In my classroom, we begin the school year by reading the various children's books that explain the theory in child friendly language. We then create our own class book of ways to fill buckets and dip into buckets.
On a designated bulletin board in my classroom, I have a sand pail that I have sawed in half. This is the whole class bucket. When the class does something that fills another teacher's bucket (eg. walking quietly in the hallway, behaving appropriately during a special area class, etc.), then the class gets "warm fuzzies" (pom poms) in the bucket.

When the class bucket is "overflowing" with warm fuzzies, the class gets a reward of their choice. When an individual bucket is "overflowing," the bucket is emptied and a sticker goes on the outside of the bucket and the child gets a special certificate for being a bucket filler.
Want your students to show kindness? How about your child at home? Why not try and introduce the bucket philosophy?