Tibouchina are warm-climate shrubs and trees which do very well in our Sydney climate. The big purple-flowered ones are the most well known, but there are also some attactive smaller-growing types. One I really like is Tibouchina 'Elsa', which has velvety leaves - which are attractive all year round - and upright sprays of small white flowers with contrasting purple stamens in late summer.
It probably flower best in sunny spots, though can tolerate a little shade. It likes to have organic matter dug into the soil at planting time and appreciates watering in its early years. Once established, it seems quite drought tolerant. I prune this one back in late winter to keep it compact - its height appears to be around 1m. I enjoy the colour of its flowers with silvery leaves, like that of Plectranthus argentatus and deep purple or maroon flowers, such as Salvia 'Purple Majesty' and Amaranthus caudatus, to echo the striking colour of the stamens. Purple foliage plants, such as Euphorbia cotinifolia and dark-leaved Canna are also effective with it.
Post script: I no longer grow this plant as it didn't seem to like where I planted it in my garden! I sometimes see it and admire it in friends' gardens.