Here's a step-by-step project for fall. In this painting of pumpkins, we'll be doing wet-in-wet minglings, negative painting for depth, and transparent layering -- as well as using warm colors in the foreground and cool colors in the background.
Prep the following paints for your underpainting: New Gamboge, Quinacridone Rose, and French Ultramarine.
For your underpainting, first wet your paper with clear water. Then, paint the yellow in the bottom third, the rose in the middle third, and the blue in the top third, letting them mingle together. Spatter some of these colors, too, and lay it flat to dry. When there is just a sheen on the paper, sprinkle some salt all over. . .
When the paper is totally dry, brush off the salt. Use your fingernail or a credit card if you need to -- just make sure all the salt is off. . .
Draw two big pumpkins in the foreground -- one slightly below and overlapping the other one. Indicate a shadow under the back pumpkin . . .
Now, paint the negative shapes -- the area around the pumpkins -- with the Quin Rose and the French Ultramarine. (Hint: Turn your painting upside down to paint the negative space. Start painting the rose wash around the pumpkins, gradually changing to a blue wash) . . .
After this is dry, draw about three more pumpkins (or partial pumpkins) behind the foreground pumpkins. Then, paint a pale blue wash over the negative shapes . . .
When this is dry, draw a pile of pumpkins and gourds in the background -- a variety of shapes. Also, draw a simple rectangle shape, to indicate a box or bin . . .
Using a pale wash of Quinacridone Magenta, paint the background negative shapes. Paint the shadows under the foreground pumpkins with this magenta wash, too . . .
Now that we've established the depth with the negative painting, we can start developing the pumpkins, with transparent layering. Working one shape at a time, paint the foreground pumpkins with transparent washes, mingling yellow, red, and burnt orange (or burnt sienna). Paint every other shape, so the adjacent shape isn't still wet. On the background gourds, use burnt orange on some and sap green on others. . .
Continue painting shape by shape, until you've painted all the pumpkins and gourds -- staying transparent, so that the underpainting and texture can still be seen.
Mix up two different darks -- magenta + blue + burnt orange, and magenta + burnt orange. Paint the stems and the part of the shadow directly under the pumpkin. Add some darks to the foreground pumpkins. . .
Finish the painting with some blue glazing on the background gourds, more darks on the stems, and a dark blue glaze on the background shape (French Ultramarine + Magenta + Burnt Orange). . .