Our tree turned out a bit sloppy, however my two year old is very independent and wanted "artistic freedom" to smush her hands.
All you need is some construction paper, green paint, a paper plate, glue, glitter, a brown marker, and cute little hands. ;)
Have your little one place their hand in a bit of green paint that you have poured onto a paper plate. Then place their hands on the paper (at the bottom of the paper) make one hand print, then above that make two, and above that make three, etc. Then turn the paper upside down so that the hand prints face down to look like a tree. As the paint dries a bit, add a trunk to the bottom. Then use glue and glitter to make ornaments on your tree if you would like!