Break down your scene into three layers:
Foregrond, Midground and Background

1. Using the Lasso tool (L), trace out your shapes.

2. Start on the background layers. Label all layers.

3. Start with the largest areas.

4. Hold Shift to add selections, and Alt to mcut selections.

Photoshop & Illustration Techniques

(Concept Sketching, Illustration & Layout Dynamics - PS Layers, Brushes & Colouring)

Other topics today may Include: (Saul Bass, Catch Me if You Can Title Sequence, Woodblock, Collage, Montage, Paper Cut Art, Retro styling, Closure)

Below is the recorded process of using reference images to create your landscape.

Always start with the background colours by eye dropping a gradient (G)

Work from background elements to foreground elements. Notice how I broke the three plans of mountains into seperate layers, so that I can control the colour and value of each to create a sense of depth.

The lasso tool is very different from the brush tool, as it allows you to create bold and impactful marks with minimal effort.

Try to break down complex shapes and patterns into basic forms.

The best practice is to name all your layers as you go, and use folder structures (however, as you can see in the video, I have not done so, and the scene became more complex than I anticipated).

The tools that you will be using in Photoshop are:
Lasso tool (L), Fill and Gradient tool (SHIFT+G to toggle), Blur effect, and Hugh Saturation (Cntl+H)