Visit the lonely.
Spend some time visiting at your local nursing home or care center. Everyone can use a little company or festive spirit during the holidays Many places may even organize events like caroling, or let you bring in baked goods for the residents.
Pay it forward.
While getting your morning coffee or at the drive-thru, consider "paying it forward." Ask to pay for your order, and then the person behind you in the drive-thru, leaving them with a pleasent surprise when they pull up next.
Help a child.
Find individual children to help through a local school or church. Find out if they do any kind of secret Santa program or similar programs. You'll both be anonymous, but you can be sure at least one more child is having a Merry Christmas.
Remember your every day heros.
Give cards, gifts or baked goods to your librarians, fire or police department, garbagemen, mail workers, regular waitress or anyone who makes your day a little bit better.
Help the homeless and/or hungry.
Talk to your local church, food bank, or soup kitchen to see if you can help in any way.