This has to be one of my favourite subjects to paint. The amount of colours you can see in rust make it a fantastic subject where you can use a variety of watercolour techniques. And another point about this particular subject: the colour on the churns is a manufactured colour, so it is one opportunity to use watercolour in the wrong way.  

To use watercolour in the wrong way: just add white to any colour and the purity of watercolour and water becomes a mix of a milky murky non colour. So we are going to add white to a green to make a factory manufactured coloured paint. A great way to remember How Not to Use Watercolours. 

Make a drawing of the churns, the ellipses are always fun to draw! Do not draw in the lines of the wood the churns are resting on. 

The palette for the churns: yellow, a milky murky yukky green (as prepared above), a range of browns (an old palette is the perfect vehicle to mix up a range of tertiary colours) from burnt sienna to a more darker brown such as Vandyke or burnt umber, a chromatic black, and any other colours that you would like to see on a rusty object. 

Start with the middle churn. Have your palette and brushes ready. Wet the churn area, paint yellow, while wet paint green, then start adding your brown colours. Work from the top of the urn, let the paints blend on the paper. Use a very light touch brushstroke to drag paint over the green and yellow. You are just about touching the paper with the brush. Keep working, until you have used your range of colours: this took my around 25 minutes to paint working on wet, then damp then nearly dry paper.  

You could use the same techniques for the churn on the right. For the rusty tin on the left: underpaint yellow, then work from light to dark and use a chromatic black for the shadow on the side of the tin. 

For the wood: palette: yellow, payne’s grey, browns. Impress draw the marks on the wood. Wet the paper, let that soak in, paint yellow, then payne’s grey then brown. I use a biro that is inkless and impress marks into the paper representing knots and lines in wood. A great technique. 

For the area of sunlight: underpaint in yellow and over paint with a variety of brushstrokes and greens.