Choose colours raw sienna, cobalt blue, burnt sienna, neutral tint (or paynes grey which has a little more blue), beware the neutral tint will give a very strong dark colour. This composition uses wet-in-wet and dry brush techniques. Don't forget wet-in-wet needs the paper really wet and your paint will be diluted by the water - never paint to the edge of the wet part you will get a strong line. It's recommended to mix up your paint before wetting the paper!

 lightning1    lightning2    more tree 3

Roughly sketch the composition horizon line approx 1/3 from bottom. Roughly draw in the lightning bolt

Paint clean water across the top 2/3 of the painting on the right side of your lightning line and drop in blue and  neutral tint. You need really dark colour at the top, allow paint to flow and add in some raw sienna. Your colours should be lighter as you work down. At the botton try to leave a small area of white/raw sienna for the wheat stalk

 

Dry completely

Use the same techique for the left side of your composition. Leave a small line of white which is dry for your lightning. Try to avoid painting over this white line as you work down using the same colours as on the right side.

Dry completely

 

 

Add the burnt sienna / raw sienna foreground wet-in-wet try to get different colour and tones (darker area on lower left

lightning4   lightning final    
Add in darker lines with irregular strokes and using different colours and tones  

Spray on some dark tones with a toothbrush, Dry Spray on some white tones (white gouache) with a toothbrush. Dry

You can continue adding wheat stalks, try scratching the paint off with a craft knife (MAKE SURE PAPER IS 100% DRY) before scraping