For the small
spots of rust mix some Sepia ( dark brown) fairly stiff
( straight from the pot with hardly any water added.) Then
with the tip of your no2 sable brush stipple in some small random
spots of dark brown. Then mix some Burnt Sienna again fairly stiff
( straight from the pot without any water added.) Stipple
inside the dark brown spots. Try to leave a thin dark surround.
