Write and mail a long and newsy handwritten letter to someone from the following list: (a) a soldier on active-duty you know; (b) a family member in an extended care facility; (c) a missionary you support financially; (d) a friend from your past who you've lost touch with; (e) a son, daughter, mother, or father who lives away from you; (f) a neighbor you used to live near before you moved; (g) a pastor or spiritual mentor-tell them what they mean/what they've meant to you; (h) a friend who lives alone; (i) a friend who lost a loved one, went through a divorce, or was cut off from loved ones and friends; (j) your spouse.
Pack up a box of goodies and gifts for married students in seminary housing near you; OR, better yet, pick a night to sneak over with your kids and let them leave them outside the doors in a "knock and run" celebration of giving. (Be sure to let the campus security folks know you're coming!) If you do it early in December, they'll be in the stressful days of finals; if you do it late December, you'll catch the ones who don't get to or can't afford to go home for Christmas.
Take your box of goodies and gifts to that neighbor who talks too long when you visit and makes you hide when you see them because you're too busy. Stay and visit.
Using sugar cubes and frosting, have a castle-building contest with your kids.
Give generously to your local food pantry and/or soup kitchen/shelter; better yet, pack a goodie bag for the volunteer who greets you when you drop off your gift. Even better still, volunteer yourself!
Find a family in your congregation in need, and help them anonymously.
Help a single mother or father provide their kids with an unexpected Christmas experience; a show, play or movie they wouldn't otherwise be able to afford; a small amount of money for the kids to buy mom or dad a gift; a meal at a restaurant they wouldn't otherwise be able to enjoy; gifts that show you've paid attention to their likes/dislikes. (This, of course, assumes you or others have assured their basic needs are met; as all these surprises will be incongruous if they don't have groceries of electricity.)
Surprise people whose lives are now spent caring for loved ones who can't take care of themselves. Give them gifts that make them know you've paid attention to their circumstances, and where practical, give them a chance to spend a holiday evening out while you take over their role. (IDEA:) Read a book to someone whose unable to read for themselves while offering this respite care.