In large mixing bowl, cream the butter with the sugars until smooth. Add the vanilla, eggs, baking soda and salt and beat until light and fluffy.
Mix in the flour thoroughly until the dough is stiff and shape into a ball. Divide the ball into 4 parts and wrap separately in plastic wrap. Chill 30 minutes.
Preheat the oven to 375 degrees F. Remove the dough from the refrigerator and divide each part in half.
Knead each piece slightly and shape it into a roll 2 inches in diameter.
Working with two rolls at a time, place rolls lengthwise on an 11 by 16-inch rimless baking sheet and flatten with palms of hands. Roll two strips of dough out right on the baking sheet to make two strips 3-inches wide and 16 inches long about 2 inches apart. With a straight-edged knife, score into elongate triangles. Leave the dough in place and press a piece of almond onto the edge of the short side of each triangle where the trunk of the tree should be.
Bake for 10 to 12 minutes or until lightly browned. Remove from the oven and with a straight- edged knife cut in triangles while still warm to separate them along the scored lines but leave them in place. Trim the uneven edges to straighten while cookies are still warm.
Mix the ingredients for the white icing and the green icing in separate small bowls. Drizzle the icings decoratively over the Christmas trees and while the icing is still wet, sprinkle with the colored sugar or nonpareils.