Here's a great way of painting very realistic skies with watercolours.

You will need:
  • A drawing book or pad
  • Watercolour paints
  • Paintbrush
  • A mixing palette
Mix some extremely thin runny yellow using lots of water, some slightly thicker blue and even thicker grey.

It's very important that they're slightly different consistencies.
Tilt your drawing book up towards you at about 45 degrees.

Before you start painting remember one rule - once you've started DON'T stop to let the paint dry!
Start off with the yellow paint,at the top of the page.

Swirl the brush down the page to create a wash, leaving about a quarter of the paper empty at the bottom.
Straight away, put some thicker blue over the top.

It'll be watery and start to run slightly.
Make the blue thinner as you go down the page so the yellow shows through.
Lie the picture flat, and clear the excess paint off your brush.

Then do some big chunky grey clouds at the top of the page...
...and slightly thinner lines of cloud as you go down the page.

This creates a feeling of space and distance.
Now the fun bit - rolling the clouds! First dab off the excess paint from your brush. Then, simply turn it on its side and start to roll it across the paper. As it rolls it'll pick the paint up off the picture. This creates a fluffy cloud effect!
Keep rolling - and every now and then get rid of the excess paint from your brush.
When your picture is dry, mix up all the colours you've used in the sky to make a sort of sludge colour.
Use it to paint a silhouette at the bottom of your picture.
You could use thinner paint brushes to add detail.
Try different coloured skies - this one is a sunset over a city, using pink instead of yellow.
This is called "Storm At Sea" and uses different shades of grey over a yellow wash.

Try it yourself!