Draw a light guideline for the center of the face
Mark the brow line and the base of the nose
Sketch the nose bridge as a slightly curved line from the brow toward the tip
Add the nostril area as a soft triangular or rounded shape at the bottom of the bridge
Indicate the nostril openings with two oval/bean-like forms on each side of the center line
Connect the bridge to the tip with the outer contour lines of the nose
Add the tip/lower nostril area with a curved form that wraps around the nostrils
Block in the nostril wings (the sides of the nose) with simple curved shapes
Place the alar crease and the separation between nostril and cheek with a light curved line
Shade the underside of the nose (between nostrils and tip) with darker tones
Shade the sides of the nose where they turn away from the light source
Add a highlight along the bridge and the most forward part of the tip
Use soft blending for gradients and sharper edges only where form turns abruptly
Refine contours around the tip, nostrils, and nostril wings
Erase or lighten unnecessary construction lines
Check symmetry and adjust the nostrils and tip to match the angle and perspective