Lightly sketch a simple cone shape for the Christmas tree. Sketch some circles for ornaments or lights.
Sketch in some long narrow oval patches of snow. Include some where the outer branches will be and some in the main cone of the tree.
Include as many or as few ornaments and patches of snow as you would like. Keep in mind that you will paint around them, so fewer will be more simple. For a challenge sketch more ornaments and snow.
Combine cadmium yellow and a small amount of Prussian blue paint. Use this light green to paint some branches swooping down from the main cone of the tree.
Then fill in the rest of the tree with light green, keeping the strokes loose and easy. Carefully paint around the ornaments and patches of snow.
Mix together cadmium yellow, Prussian blue, and a tiny but of black paint to make a middle green. Use this color to paint a few more branches on the sides of the tree and some branch clusters in the middle.
Leave some of the light green visible, especially on the tops of the branches. Again painting around the white ornaments and snow.
Combine Prussian blue, black and a little bit of yellow to make dark green. Add this to the tree, mostly on the undersides of the branches and in shadowy patches around the tree.
Let the tree painting dry completely before adding the shadow and ornaments.
Brush some clear water on the paper below the tree. Let it soak in just a bit and then paint on some cerulean blue to indicate a light shadow that the tree is casting. When it dries the blue edges will softly blend out.
To paint the ornaments paint around the outside of each ornament then wipe the extra paint off the brush. Drag the paint toward the middle of the ornament living a small white highlight in the middle.
I used alizarin crimson, orange, and ultramarine blue for the ornaments but you could use what ever colors you want.