Choose colours lemon yellow, raw sienna, prussian blue, neutral tint (or paynes grey which has a little more blue)

the neutral tint will give a very strong dark colour

atmo tree1   atmo tree2   atmo tree final
Roughly sketch the composition, then spray or paint clean water on the whole paper. Paint on raw sienna in the middle section above the horizon line while the paper is still wet. It will look very dark but will dry 30% lighter. You can drop in more colour while the paper is wet, BUT once it starts to dry results can be unpredicatable.  

Note the pale area it's important to keep it light. While the paper is still wet drop in prussian in the sky and green with prussian and lemon in the foreground add a little raw sienna at the bottom for balance. paint in the trunks with neutral tint. Note we have not used the same colour for the whole of the trunk.


  Add in more foliage with either dry brush or a sponge. (if you use asponge don't use over the whole painting!
sloping tree final  

Put in the foliage details and small branches - Let your brush skip over the paper using some dry brush strokes on the edges

Avoid painting the trunks too thick (you can always make it thicker if too thin but the opposite is much more difficult!). Use different tones on the trunks. Don't forget the "bird holes" Draw the branches over the white areas with a rigger brush