You can prune them after flowering but the dry leaves don't sound good. Maybe you'll be able to add a photo tomorrow.

Yes dried leaves dont sound to good, has it been kept watered through this long dry spell ? if your worried that it may be dying then do a few bark scrapes if you see green then all should be well, if so and some of the plant has died back then cutting these back will result in new growth.

Garryas always look scruffy after they've finished flowering.
It's probably not putting on much fresh growth because it's so dry at present (ignore that comment if you live in northwest Scotland!). Once we get some rain, it will look much better. I have a wall-trained garrya, and I prune to within about one bud of the old wood each year

I've managed to add a photo now, I think one may of been too big to add. Jackie :o)

Yes, that's how they tend to look at this time of year. A bit of rain, and it should start to look better in two or three weeks as it put on new growth

Andrew. How hard can I cut it back? as I really want it a lot smaller.

If you look at each stem, you will see raised ridges on them. Each ridge contains a dormant bud, so you can cut back to just above one of them. If you want to reduce the bush drastically, I suggest you do half of it this year, and the rest next year; this will not be such a shock to the plant. I would also give it a good feed and keep it watered in times of drought to ensure it recovers and grows away well.

Thank You Andrew :o))