References

Before starting drawing sky, Choose what kind of sky do you want to draw.Search for some references as much as you need to help you. What kind of mood do you wanna show? This will affect your choice of colors.

I'd like to draw a dramatic sky for this tutorial, therefore i search references cloud with strong lighting.

Sky

Fill the canvas with base color of sky, i choose blue.

Add darker blue on the bottom. I used design pencil and blur tool.

Clouds

Use csp cloud brush with large size, paint the base color of the cloud. I use blue-grey for this one. Use the same brush to erase the cloud and shape it.

The light source is from left side. Make new layer, paint orange clouds on the left side of the grey cloud, make it look puffy. Add lighter color of orange or yellow at place where the strong light touches the cloud.

Blur the orange cloud, make it more blending with the grey cloud. Blur on the right & bottom side to maintain the shape.

use smaller size brush, and paint darker clouds to create sense of depth.

Erase, re-shape and blur the dark clouds.

Almost done!

Draw silhouette of trees, buildings, as foreground.

And a cat, don't forget cat!

It's done! It's finished!

Congratulation! You reached the end of my tutorial. Don't forget to experiment with cloud brushes ^^

This is my favorite brush to draw clouds. I have other brushes, like yuumei's cloud brush, etc, however i used this one for this tutorial.

You can use different brush clouds, play around with the shape until you get a nice, puffy clouds.