Here is a fun exercise, it practices wet in wet technique and also the ability to paint accurately as well as carelessly. It also exercises the ability to perceive and reproduce fine value differences. Since it is painted with only two colors, it is also a good exercise in color mixing technique.
My choice of colors for this is French ultramarine and burnt sienna. It works with any blue and brown combination. Test first so that the selected colors can give a neutral black mixed with each other.
Usually I finish with the shadows, but I was worried that the blue squares on the towel would dissolve if I painted shadows over them, so for that reason I started with shadows.
This painting does not do well in large format, make a small painting of this.
Some of the shadows have a clear edge, others have a smooth transition from shadow to highlight. Painting a surface with a hard finish is easy, you just have to stop painting in a certain place, it is more difficult to achieve a smooth transition.
Paint it like this: The shadow should be painted until it starts to lighten, wash the brush in clean water, paint with water along the edge of the still wet shadow (not in the shadow, just along the edge) the color of the shadow will follow out into the freshly painted water but not all the way. If necessary: continue with more water outside until a fine gradation occurs. It may take a while to paint all the shadows, do not rush. Paint all the shadows you see in the photo (more or less).
There is variation in the blue lines: they are thicker or narrower depending on perspective and angle. They are darker or brighter depending on how the light falls. Sometimes there is a break in the line when it is hidden behind a fold. They form an intricate pattern so study them carefully, you should not merely paint blue squares, but try to imitate the photo with all the folds, highlights and perspectives.
I added brown in the blue color to soften it a bit.
Now only one black chess piece remains, it must be very black,
A dark color is mixed with brown and blue, depending on which you have chosen, it may not be possible to make the mixture really black, but do the best you can. Paint the ENTIRE piece except for a few small clear glitters, they should be completely white. Then, before the paint is completely dry, lift up, with a damp brush, some highlights in the base and elsewhere, they should not be completely white, only a little lighter than the rest.