This year's growth on hedges is beginning to harden up now, so give a final trim before it gets too tough. If you have a fuchsia hedge however, it's still in bloom, so leave it be. The accepted practice is to do the trimming in spring, allowing the old growth to protect the plant during winter. (Despite this, I know a fuchsia hedge in highest, coldest Wicklow that is trimmed in autumn, with no ill-effects.)
When clipping a hedge, shape it so that the base is slightly wider than the top. This way, air and light can get to the whole surface, making for a thick, even hedge with no gap at the bottom.