I confess, I am not much of a winter gardener. I try, but when it is so cold, damp and uninviting I find plenty of reasons to think about gardening rather than any actual doing.
For this reason I prefer Winter colour in my garden to be maintenance free, so I can look at it from the warmth inside.
Mahonia is the easiest to grow and this variety M.media flowers bright yellow in December & January, some such as 'Charity' are scented. If you want to have a shrub border with all round interest and very little maintenance, Mahonia is worth checking out.
Whilst Mahonia is happy growing just about anywhere, (hence it is a landscaping favourite) Hamamelis the Witch Hazel is more temperamental. I have seen it looking lovly in other people's gardens; it seems to shimmer in the gloom but no hope of growing it myself.
Hamamelis needs to be planted in a sheltered spot, away from cold winds and not too wet as they dislike waterlogged soils. Hamamelis need sunny to produce good flowers which come ahead of the leaves. An added bonus is that Hamemelis have good autumn colour and if you can grow it in your garden, best plant it where you can see it's flowers from the comfort of your armchair.