Classical realism or figurative art is what requires the most abilities and technical expertise. This is what I'd like to talk about today and give some random advise to those aspiring realist painters.
As far as brushes are concerned, you should have many brushes so that you would not lose time washing them while working. Take a new brush for every new mix. Brushes should be treated very carefully. After every session they should be washed in turpentine or paint thinner and after that in warm water with soap. When drying them it is better to dry them in an horizontal position so that water does not run inside the ferrule and rust and unglue the delicate work inside there.
After work wash the palette with turpentine and scrape it with a razor. Before work wipe the palette with linseed oil. That will allow the new paint mixes to be cleaned easily.
The canvas should be primed additionally a few more times with gesso or flake white. Finally it should be ground with fine sandpaper. After that the canvas should be scraped with a razor to remove the canvas texture till smooth dead surface similar to the egg's surface is achieved.
The drawing is made on paper and life-size to the smallest details. Then it is transferred to the canvas by carbon-paper. After that the drawing is outlined with brown ink because the first oil layer, called Grisaille (transparent coat that is equal to the middle tone of largest, lightest object in painting) - will wash away the pencil, but the ink will remain visible almost through the last layers. I do not always do this, but always have brown outlines in oil paint and turpentine. Those will also last to the last layer if you let them dry and are careful.
Before each new layer the canvas is carefully wiped with linseed oil. After that the canvas is wiped with a soft piece of cloth to remove the excess.
There are many mediums on the market and I prefer my own Maroger medium made at home, the Titian formula with wax and the Rubens formula with mastic varnish, resembling honey.
The basic set of paints is the following: Flake White, titanium white, Yellow Ochre Light, Red Ochre, Burnt Umber, Raw Umber Ivory Black, Naples Yellow, Cadmium Yellow Deep, Madder Lake Deep, cadmium red, ultramarine blue, viridian green .
For the grisaille layer or the first paint layer: The canvas is covered with a liquid mixture based on Red Ochre, Yellow Ochre Light and Ivory Black and flake white.
The shadow (the process of creating intermediate layers) is made with Burnt Umber. In the second layer all details are made excluding the texture. In the third layer of the main tone masses is made with a big brush.
The light is made with white lead ( flake white), light ocher, red ocher, and burnt umber. The aim of this layer is to create shadows. The picture must look as if its objects were lit with moonlight - olive cold gray color. Colors are applied thickly, half a tone higher, shadows are very transparent, half a tone lower.
The first and the second flesh tones: main life colors layers is made half a tone lighter and two tones lighter in colors; and half a tone darker and two tones lighter in shadows.
Details of textures, thickly applied highlights, bright reflections. In this layer you may use additional paints: blue, red, yellow (cadmium yellow deep), madder and more.