Same as others, layers and keep away from cotton. Something even I'm only really starting to properly outfit my wardrobe with, because sadly, building up a good selection of quality pieces does add up in cash.

But perhaps more importantly, you're just going to have to experiment with what works for you and your husband, and the activities you do outside. My body creates so much of its own heat I run extremely warm and think that if I wore as many layers as a lot of people do I'd just be burning up and sweating. Even at night I have only one summer duvet for a blanket while my wife piles up 3 thick layers on herself, we have such wildly different warmth needs. It's probably why I've been able to get away without having proper layers myself for so long...