I did a really good and easy xmas tree craft today with under 3 :

made them paint a paper plate in green, sprinkle some red sequins...
cut plate in 4 and voila 4 xmas trees.
put a brown paper square for tronc.

I stapled 4 on a lengh of black wool with a regular space in between and a hoop at top.

looks really nice 4 dangling trees

hope i'm clear. it's easy and effective

OOOh and we put a golden star on top of each tree