Build the form in three staged steps
Followed his teacher Chistyakov's system: first the placement in space, then the proportions of the large parts, and only then the likeness of the smaller forms.
Why it matters · The order is the point. Moving from the general to the specific means the likeness rests on a structure that is already true. Fix the placement and the big proportions first, and you never get lost polishing a feature that sits in the wrong place.
Pavel Chistyakov's three-stage drawing method (placement, proportions, likeness), documented in Yu. A. Manin, P.P. Chistyakov and His System of Teaching Drawing, 2017
Draw so the unseen parts can be felt
Took on Chistyakov's principle that you must understand a form so fully that even the parts of it you cannot see are accounted for.
Why it matters · It is what gives a form real volume. A head drawn this way is not a flat profile, it is a solid skull turning in space, so the finished portrait carries a weight and roundness that copying the outline alone can never reach.
Pavel Chistyakov, "the invisible parts can be felt," quoted in Arthive, 2021
Work long to keep the picture fresh
Painted The Girl with Peaches for over a month of near-daily sittings, wearing the sitter out to hold the living quality of light he saw in front of him.
Why it matters · Serov drew a line between a picture that is merely correct and one that feels alive. Chasing that freshness, even at the cost of exhausting a sitter, was how he got the feeling of a real moment into a finished painting, a quality he prized in the old masters.
Valentin Serov, "I painted it for over a month and tortured her... to preserve the freshness," quoted in Igor Grabar, Valentin Serov: His Life and Art
Command every medium, not just one
Held that an artist must be adept in every available medium, from oil and watercolour to gouache, tempera, pastel, and charcoal, because nature is that various.
Why it matters · The range gave him the right tool for any subject or effect. It also shaped his teaching, where he pushed students toward broad technical command rather than settling into one medium, which made them more adaptable.
Igor Grabar, "Serov believed that the artist ought to be adept in every available medium," The Tretyakov Gallery Magazine
Teach by drawing beside the students
In his classes at the Moscow School he often drew from the model alongside his students, a silent working demonstration they found more useful than any lecture.
Why it matters · It put his decisions in plain view. Students watched him construct the form, catch and correct an error, and solve a problem on the page in real time. That is direct transmission of a method, not theory about one.
Nikolai Ulyanov (student) testimony and his drawing, Serov and I at the Moscow School, 1901 to 1902