Here are the key pastel techniques that Paulette Gautier masterfully employs in this rose bouquet (and that are visible even in a photograph of the work)
Look at the background and the golden cloth: she lightly drags a lighter pastel (sage greens, pale ochres) over darker underlying layers so the lower color peeks through. This creates atmospheric depth and that delicate “bloom” typical of pastel.
Velvety layering & blending (sfumato-like)
She builds the petals with multiple thin layers of pastel, gently blending them with her fingers or a soft stump to create that creamy, almost luminous transition from light to shadow. This gives the roses their characteristic powdery softness and the illusion that light is glowing from within.