When it comes to plant pots, more is more. For a stylish display, gather together different shapes and sizes and paint the pots in tonal shades. "If you group containers together, the space looks well filled and abundant," says Isabelle Palmer of The Balcony Gardener. "Using uneven numbers of pots and planting in odd numbers will give the most impactful look." Keep your plant colour palette simple - just shades of green, for example - to make sure your display looks vibrant rather than busy.