Draw the fish and lily pads on the canvas, then mask them off with a product like Clear Cover or an equivalent.
Painting the background
Mix the acrylic paints you will need to do the background. Thin with a bit of water if necessary.
Follow the technique that Nolan uses to cover the canvas in background colour, blocking in the different tones and then blending them. Dry the painting and clean the palette before proceding to oils for the next stage.
Mixing the koi colours
Mix the colours that you will need for the koi. Include variations for highlights and shadows. Note that you will need to mix some ground colour also for the shadows.
Painting the koi
Begin by unmasking the fish from the canvas. Save the masks in case you need them later.
Start out by painting a light coat of colour to make the markings on the white koi. Your markings will be contoured to the shape of the fish.
Next, block in the white parts of the koi. Then add the shadows, starting at the darkest side. With a dry brush, lightly blend in the shadow to the white. As you create these contrasts with your shadow tones, the fish will begin to look rounded.
Be sure that the white areas have paint as the white will become the fish's highlight colour.
Now add the highlights and shadows to the koi's markings. Add more interest to your painting by varying the hard and soft edges to these spots.
Paint the fins next. Starting with the tail fin, paint in the lights, then the shadow tones. Note how the proper placement of shadings gives the fin a slight concave shape. Next do the other fins, following Nolan's lead.
Move on to the eye. Adjust your dark shadow colour and paint in the eye oval. Note the technique Nolan uses to indicate how the eye protrudes. Mix up a bit of sky colour to highlight the eye and follow it up with a glint of white.
Go back and adjust the shadings on the back of the fish. When doing shadows on the koi's markings, be sure to use the marking colour as the base for the shadow tone.
Painting the lily pads
Remove and save the masks from the lily pads. Block in the green shades; blend them, then add the darker colour on the edge to create the curling effect. Add the impression of ribbing on the lily pad. Highlight and shade the middle vein.
Finish up by adding highlights around the edge. Notice how it defines the thickness of the lily pad.
Use the same techniques to paint the other lily pads.
Creating the underwater reflections
Let your oil painting dry several weeks before proceeding to the next step.
Mix a sky colour to use to create reflections on the water.
Again, mask the lily pads. Then apply a light wash of the sky colour to create a smoky effect over the water. Add a ripple or two for interest.
Using your sky colour, place cast shadows under the lily pads.
One last look
Make one last sweep of your painting and make any adjustments needed.