What are some family tradition activities I could do with my preschool class?

Try wrapping "presents." They can be empty boxes. As a matter of fact, I would show them they are empty so no one tries to open them. :^) Wrapping is a good fine motor skill, and every family does it. The ones they wrap will look funny, you can be sure. But they will be so proud of them! Put them under your classroom tree.

Most families do special cooking or baking. Why not read "The Gingerbread Man" and make gingerbread cookies? Instead of using a cookie cutter, they can use the dough more like "playdough" to make their men. Make and flatten a smaller ball for the head and a larger ball for the body and put them together. Make snakes from the dough and cut them apart and attach for the arms and legs. Use red hots, raisins or whatever for the features and buttons.

Jan Brett has written The Gingerbread Baby and it is a cool book!

I do not think it is a family tradition, but The Reindeer Pokey is a fun dance. It is to the regular Hokey Pokey tune, except you use reindeer body parts:
antlers instead of head
**you might want to add "red nose"**
hooves instead of hands
Bushy tail instead of back side
"You do the reindeer pokey and you turn yourself around. That’s what its all about."

why don’t you send something to the parents and ask what their family traditions are and then you can do the ones that your kids do with their families. they’ll like that because then they’ll be able to guide you along and tell you why they do certain things.

You could try making cookies with the children. This will allow them to show how they leave cookies and milk out for Santa, and also a nice treat for the children to enjoy!

Also, you may ask them what songs they sing at home and the class can sing that song together.