Scale, colour and the rule of thirds

SCALE — the arrangement should be roughly 1.5 to 2 times the height of the vase, and 1 to 1.5 times its width. A tiny posy in a tall vase looks lost; a fountain of stems in a tumbler looks comic. The vase is half the design.

COLOUR — three palettes are reliable for beginners:

• Monochrome: one colour, many shades — all whites and creams, or all dusty pinks. Almost impossible to get wrong.

• Analogous: colours that sit beside each other on the colour wheel — peach + pink + apricot, or blue + purple + plum.

• Complementary: colours opposite on the wheel — orange and blue, yellow and purple. Loud but the most photogenic.

RULE OF THIRDS — place the focal flowers slightly off-centre, never dead middle. The eye finds asymmetry more pleasing. Imagine three vertical zones in your arrangement; place focal flowers in zones 1 and 3 (or 2 only if there's a single huge bloom), leaving zone 2 lighter.