Any nice cashmere beanies in a neutral colour?
Cos is always my go-to for classic cashmere beanies. https://www.cos.com/en_gbp/women/hats-scarves-and-gloves/hats.html
This isn’t cashmere but the Acne beanie is by far the warmest I have had
Arket also have great ones - https://www.arket.com/en_gbp/women/accessories/hats-and-gloves.html
Can’t go wrong with this 100% Cashmere Knitted Beanie | UNIQLO UK
This one from Everlane looks fab too