Yew is perfect for creating topiary. Plants can be bought ready-trained or you can use metal frameworks to guide you when trimming.
Yew hedges can be easily maintained by trimming once in summer or early autumn
If a yew hedge becomes overgrown, it is possible to renovate it over three years. Mid-spring is the time to do this. To recreate a dense, even surface, cut the top of the hedge back to at least 15cm (6in) less than the final desired height. The following year, reduce the width of one of the sides, followed by the second side in the third year. A neglected yew hedge, with bare trunk at the base, may benefit from coppicing, cutting back the top-growth to within 15-20cm (6-8in) of the ground in early spring. This will produce multiple stems which can be trained into a formal hedge. The disadvantage to using this method is the length of time taken for the hedge to recover, which will be several years.