There are several shrubs that I would recommend. One of the most strongly fragrant is Daphne bholua ‘Jacqueline Postill’ which has a powerful, sweet, delicious scent which wafts through the air for several yards.

It produces star-shaped, pink flushed white flowers from January to April.  It prefers full shade or a sheltered position.

The Bush Honeysuckle, Lonicera fragrantissima  and Wintersweet, Chimonanthus praecox are both deciduous shrubs whose flowers are borne on bare branches.  The former has very fragrant, creamy-white, tubular flowers in winter until early spring and is best grown in full sun.  The Wintersweet has sweetly scented, light sulphur-yellow, small, waxy flowers with brownish-purple inner petals.  Grow it against a warm, sheltered wall in full sun or part shade, in free-draining soil.

Witch hazels have amazing scent and the colours range from pale lemon to dark red.  Hamamelis x intermedia ‘Sunburst’ has large broad leaves which in autumn turn from pale yellow to deep orange.  It produces clusters of lime-yellow, crimped petalled flowers, on bare branches.

The Lily of the Valley Bush, Mahonia x media, is an evergreen shrub with attractive spikey foliage and fragrant, showy, bright yellow flowers from late November to March, followed by edible black fruit.  This plant prefers partial shade and well-drained soil.

My final “must have” plant is Sarcococca ruscifolia, Christmas Box or Sweet Box, a compact, slow growing evergreen shrub, with dark green leaves.  This produces strongly, sweet scented, creamy-white flowers from December to March.  It thrives in dense shade but will tolerate full sun to part shade.