It's very simple:
First sketch out the leaves and flowers on a piece of paper, trying several colour variants and proportions to see what looks best.
Starting with the dark purple colour on the right, draw short lines one below the other, more or less parallel. Use the lighter hue on the left, hatching in the same way. The flower heads should look fairly long and thin.
Go over the outlines in white: this makes the flower stand out better. Use the same technique with the stalks and leaves: the darker hue on the right and the lighter one on the left. This progression indicates the direction the light is coming from. Use grey for the outlines and for a few highlights in between.
It’s entirely up to you how you arrange the sprigs of lavender round the pot. When you’ve finished, brush or spray the decoration with clear varnish so that it resists splashes and wiping. The same applies on a wooden surface, but in either case it looks better if you use a matt varnish rather than gloss.
Be brave: experiment! Try out different shapes and colour combinations (lavender comes in many shades from violet to mauve, light or dark). You can also use the design on other objects and surfaces such as candlesticks, napkin rings, recipe books, gift boxes, or colour some attractive stones as in our photo.