A practical guide to flat, graded and variegated watercolour washes, covering how to mix water and pigment, what each wash is for, and how paper and drying times affect the result.

Ten common perspective slips in one-point and two-point drawing — drifting horizons, leaning verticals, lazy ellipses and wrong scale — with quick fixes for buildings and interiors.

Cross-hatching and tonal shading both build light and shadow, but each suits different subjects. Here is how to choose between them.