An optional but beneficial step; you need to decide on mood/tone for the overall piece and consider your palette. Color-thumbnails work best for this. I was a deviant and did a quick black and white sketch instead. I usually use a new layer to block out my general idea. Use whatever tool you are comfortable sketching with! Make sure to draw on a new layer and not the canvas.

I usually shrink the sketch to a thumbnail so I can reference without it obstructing too much when painting. I lay down a base color on the canvas, and you can use the fill bucket for this. I also roughed in a few horizon lines with the oil pastels for reference.

From here on in it's mostly just painting. I use the Chunky Oil Pastel tool, but you can get nice effects with any of the pressure sensitive brushes, so experiment! I set the eraser end of my stylus to blend by using it to select: Blenders -> Grainy water. I switch back and forth between painting and blending often while working, so this is very useful! As you can see, roughing in large areas of color and determining a light source early is important. I use a fairly large brush for this stage.

I usually just use the basic paper and tone it down by setting the paper’s scale to 30% and the contrast to 20%. I set my oil pastel to about 60% Opacity and 80% grain, and using a large brush start roughing in the lights and darks. It’s vital to work out your light source! See ‘side tips’ at the end of the tutorial for some thoughts on how to choose colors.

I continue roughing in the scene with large brushes, blending along the way. I always work in terms of distance- the sky is farthest from the viewer, then the distant hills, then the foreground. I don’t use layers for this but if you want to there is no reason you can’t! It makes fixing things easier down the road. I am a traditional painter stuck in a computer, so to speak, so I tend to work most things up on the first layer- or in this case, the canvas. Work with as many or few layers as you like! I hid the tumbnail layer for now. You can hide layers by clicking on the eyeball icon next to them.

It’s time to start refining detail. Again, I work from back to front, so the sky is first up. It’s important to note that I work details gradually over the entire area, which helps to keep any one area from being overworked and keeps the painting consistent.

I use the Eyedropper tool often to pull all my colors from the existing painting to keep the colors uniform. It’s important not only to remember the direction of your light source, but the color as well. Highlights are not always white after all! Clouds, being mostly water vapor, are very good at refracting and reflecting light. You may be surprised by what colors you are using.

With consecutively smaller brush sizes, I am going in and detailing the clouds. Clouds aren’t solid, but from afar they appear so. Areas of highest contrast (such as where light strikes the undersides) have the sharpest details. If you like a soft, dreamy look, you can stop here, but I like my clouds to have a little more detail. It's important to remember the shapes of the clouds vary depending on moisture, altitude, and a number of atmospheric conditions. Fluffy clouds are simple but not always realistic. As with all art, researching your subject matter will help you paint it with greater skill.

I could continue to refine the clouds indefinitely, but it would be easy to overdo it. There is more atmosphere and haze between the viewer and distant clouds, so those are softer and less detailed. It may be tempting to rush through this stage, but a hasty background can ruin an entire painting. These clouds took me many hours.

When painting strong directional lighting, it’s tempting to highlight everything, but this will kill the effect of having the directional light. You must carefully consider the shape and form of everything in your painting to learn where the light would strike. Study them to figure out what shape the clouds must be to catch the light as they do.