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A good waterproof, layers you can remove easily, hat, gloves all help, as do good socks. It doesn't have to be specialist items, although these are nice if you do a lot. I use a walking pole too, find it helps with downhills especially.
I always carry a survival bag, it might sound extreme but if you/ someone else turns their ankle, and are still for s few hours awaiting rescue it could make a difference. Ditto map, compass, whistle, mini first aid kit, hand gel ( had this pre Covid, useful before eating lunch), tissues and spare high energy snacks. A flask for a hot drink and a hot food flask can make a big difference in winter. I also keep extra water in the car. I have an insulated folding sit mat for lunch/tea stops.
Pathfinder books by ordnance survey offer some lovely circular routes which are easy to navigate.
Make sure someone knows where you are going and when you will be back. Enjoy the walks and smile/say hello to your fellow walkers.