I'm a big fan of hedges. and it's probably the Ladybird Books that are to blame. Ladybird Books were a big deal when I was growing up, and they were full of ecology; trees, the countryside and even an entire book on hedges. When I moved into a house with a rough patchwork of fences, I went to the internet and bought a native hedge. It arrived in the depths of winter, unpromising twigs wrapped in black plastic. Look at it now:
It's a deliberate height to screen, being an urban garden, but it's hit that awkward point where it sees the possibility of trees in its future and starts shooting for the sky every moment your back is turned. You can just hack it back with an industrial strength trimmer of course (that is the country way) but you can also do what I'm doing here, which is taking out branches that are trunking and leaving the thinner, bushier growth. Where you cut, you get a puff of fresh growth, so lots of cuts at different heights fill out the hedge and make it bushier. Kind of like layers in a haircut, but for hedges.