We'd like some advice on creating a sub-tropical courtyard that would also reduce the view of neighbouring walls and fences.

Use foliage to disguise and soften walls and fences. To avoid a boxy look create garden beds using curves or diagonal lines. Large pots are good focal points, as are sculptural plants, such as imperial bromeliad (Alcantarea imperialis 'Rubra') or agave (Agave attenuata). Tropical-style gardens ideally have three layers of height, with foliage, colour and texture. For the tallest layer, try clumping bamboo (it's non-invasive), lady finger palms (Rhapis excelsa) and golden cane palms (Dypsis lutescens). Within the middle layer you could use cascade palms (Chamaedorea atrovirens). To add colour, try foliage plants, such as Fijian fire plant (Acalypha wilkesiana), variations of ti plant (Cordyline fruticosa), ornamental gingers, variegated yucca (Yucca elephantipes 'Lemon') and cannas. Moses-in-the-cradle (Tradescantia spathacea), variegated mondo grass, Liriopes and clivias are good for the lower layer. For an instant tropical look you could cover fences with bamboo products such as Natureed from House of Bamboo.