Sketch or paint a scenery and give it to someone you love and care..
Do you have a xmas tree wish list at major stores with kids names on them,you could buy them a present and leave it under the tree.
Give money to charity, not only will it make them happier but it will also make you happier knowing that you could make a difference to someone's life.
Smile at a stranger! Most people will smile back and then you'll both feel happy!
volunteer and be nice to people...a sweet smile will do ease up a tired person working all day....
Volunteer for a good cause
Take a day and treat yourself to a massage or just make it your day.
Just be yourself. you will be surprised who well you will turn out to be.
Just Be happy and smile
i dare you to walk up to a homeless person and give him 500$
Well I have ideas but I'm not sure if they qualify as nice