Privet will grow almost anywhere. It's able to cope with sea winds, full sun, partial shade, light, dry and sandy soil. They'll put up with almost anything but a very boggy soil.
The cheapest way of creating a privet hedge is to buy bare-root plants anytime from November to March.
Prepare the soil by digging in plenty of well-rotted organic matter. Plants are fast-growing and appreciate a good soil and a sprinkling of bonemeal to get them going. Dunk the bare root plants in a bucket of water while working out the spacing. For a long hedge it's often quicker to dig out a planting trench than make individual holes. Plant each plant about 30cm apart and make sure you plant them at the same depth they were on the pot or look for a soil mark on the bare root plants. They won't appreciate being planted too deep. Firm plants in well and water.
These tough plants are very easy to propagate. Simply cut healthy stems about 10cm long from the parent plant on a warm autumn day. In a position of dappled shade loosen the garden soil with a hand fork. Remove the lower leaves from the cuttings. Push about 4cm of the leafless cutting stem into the soil.
By mid-spring in the following year the cuttings should be showing signs of growth. Pot them on or plants them directly out in the garden.
Privet is generally a trouble-free plant. However, wet root rot can be an issue if plants are planted too deep in a very wet soil. Plants will be stunted in growth, leaves turn yellow or they drop. Young hedges may need to be replanted and the soil drainage improved.
It's unlikely that a mature hedge will suffer if it has established itself in the soil.