You will need:
Step 1 and 2:
First, I make a pre-sketch. It doesn not have to be exactly as it will be covered by the colours. Nevertheless, it helps to determine the proportions. The masking tape increases the contrast between the gouache application and the dark paper.
Now I roughly apply, beginning from the top, a mixture of Magenta 325, Scarlet red 314 and Vermilion 312. Down to the bottom, I lighten the mixture with Naples yellow reddish 311, Naples yellow light 201 and Permanent white 199.
Now I take the wetted big flat brush and move it from left to right to create a smooth colour gradient. For the bottom part of the painting I use the same technique to create the reflections onto the water.
Step 4 and 5:
As soon as the sky is dry, I use a mixture of Turquoise bluish 551, Naples yellow 201 and Permanent white 199 to paint the mountains. I take a small brush, beginning with the light mountains in the background to the darker ones in the foreground. With pure Turquoise, I paint a stripe of meadow underneath the mountains.
For the sidewalk, I use a mixture of Permanent white 199, Naples yellow light 201 and a little Ivory black 788 for a flat application. The space in between will be filled with a greyish lightened Indigo 438. Therefore, I combine a little Permanent white and Naples yellow with Indigo and a little Ivory black.
Step 6 and 7:
For another meadow I use, as for the first one and the mountains, Turquoise bluish 551. I leave some free spaces for trees. For the shadows which establish a border between land and water, I use Ivory black 788, slightly lightened with a little Indigo 438.
After drying, I add three stripes for the terrace: a wide one in the same colour I used for the sidewalk (a mixture of Permanent white 199, Naples yellow light 201 and Ivory black 788). Besides the sidewalk I add a thin, dark grey stripe and then the third stripe, mixed of Permanent white 199 and Ivory black 788.
Step 8 and 9:
Now I paint four fir trees. You can use a pencil for a thin sketch which will be filled with colour. Or you paint the fir trees with rough, even strokes in a zigzag line from the top to the trunk.
With a cutter, I cut tree shapes out of a piece of paper and put them onto the turquoise stripe underneath the mountains. I put the sponge into a little un-thinned Indigo and carefully dab the colour onto the pattern.
Step 10 and 11:
Now I add some more details with the brush, as e.g. the trunks. I can also correct uneven forms. Then I repeat the procedure for the trees for the water reflection.
With Naples yellow light 201, I paint the clouds onto the red sky. For the shadows, I use a grey which I apply with the sponge.
Step 12 and 13:
With a thin brush and Ivory black 788, I paint a small fence which overlaps the trees.
With a simple cork, I can print the even, structured with gaps circle of the sun/ moon.
Step 14 and 15:
The fir trees get a pattern with small stars, painted with Turquoise bluish, to create the thistly impression of conifers. For the meadows, I chose another pattern: two small strokes, symmetrically spread over the meadow, symbolize blades of grass.
Finally, I paint a wall pattern with lines parallel to the sidewalk. As a last detail, I add some small lanterns near the sidewalk.