Santolinas, silvery grey, scented foliage; berberis nana, purple mounded foliage; all low. Abelias, autumn flowers virtually evergreen and choice of foliage ; potentiallas for summer flowers; I agree with grasses that provide movement and height; choisyas with yellow or green foliage and sweet smelling flowers in spring/early summer; buddleia Harlequin with variegated foliage; Olearias, Berberis Darwinii (orange flowers in spring), philadelphus (scented flowers in June), hibiscus (flowers in September) and what about the hollies? A hedge need not be about the usual hedging plants. I grow a "hedge" along the side of my veg patch comprising euonymous emerald n gold, variegated box, potentilla, a good blue rosemary, Lonicera nitida Baggesons Gold (love this one) and a couple of half standard prunus cistena crimson dwarf. It looks pretty good, I think, with all year round interest and colour with easy maintence. I would let my imagination go wild...