Visit the elderly and bring your pet
Donate some winter jackets, boots, hats, gloves, scarves
Volunteer at a soup kitchen
At our grocery store, there is always a shopping cart when you leave where you can drop food in that goes to an organization who are collecting dry goods
Donate blood
Leave a note on a strangers car
Go to the Red Cross website and you can send a holiday card to a service member
Pay for someones coffee/meal