I'm painting a backdrop for a layout that's set in the Mount Lofty area of South Australia. It's O scale, and a section of about 4 metres, but only about 30 cm high.The board was already painted sky colour (housepaint will do for that).
Brushes: two foam brushes (1 inch and 2 inch wide). One soft mop brush. Half-inch and 1 inch flat brushes. One fan shaped brush. One rigger brush. One sea sponge.
The paints are mostly cheap acrylics, whatever was on hand.
As I'm not familiar with the landscape of the area, I referred to photographs.
I painted the clouds first, using the soft mop brush to avoid streaks and hard edges.Then the hills with the larger foam brush, keeping the top of the hills soft.
I used the sponge to make some rough bush/tree shapes with a mix of pine green with added phthalo blue and phthalo green (not completely mixed in). Some of the shapes were smudged a little.
When that was all dry, I started painting the detailed trees, using the flat brushes. For some of them I also used the corner of the small foam brush. For the gum trees I used the fan shaped brush, dipping it in sage green and darker green so that I was painting two colours at once. Then I painted the trunks and branches with the rigger brush.