With Winter now setting in, the structural and evergreen plants really start to come into their own and provide interest through the bleak and barren months. Two shrubs, Viburnum Tinus and the lower growing Viburnum Davidii, are invaluable at this time, suiting most situations and soils and also flowering at this time. Also, Holly!
Hellerebores are excellent evergreen plants but are slightly more fussy. Most normally like a bit of shade and some richness in the soil. Cut away any brownish/black leaves at this stage to keep them looking nice and green for the winter.
Some herbaceous plants such as many grasses, Sedums and Asters (particularly Aster Laterifolius) keep lovely structures throughout the winter so could be left alone rather than chopped back. Many plants leave brown seed heads at this time which can be left as food for birds.
Variegated plants are also very good now, giving a brightness to the scene. Excellent shrubs are Euonymus, Rhamnus and again, Holly!