The trick is breathablility especially if you are wearing the stuff & being active. Sweat is what makes you cold. I dress differently depending on many factors. Wet cold, dry cold, moving, standing, etc. I will swap my layers out too, mid day, socks especially if I'm moving a lot. My outer layer, coat & pants are insulated but with vents. You open them up to let the moisture escape, especially if you are moving. You can shut em down when you stop moving.
Check the labels or description of what the item is made of. I do not use any cotton whatsoever since it holds moisture. Not good! Most Under Armor Type shirts are 100% polyester. Most wicking material is a mix of polyester & spandex. The spandex lets it breathe better. Socks with Merino Wool 80% & up with a mix of spandex & polyester work the best imo. All the winter training with the Mountain Division taught me something.
It doesn't have to be expensive either. I shop Target, Marshalls, TJ Maxx, Dick Sporting Goods, Gander Mtn or Kohls-brand for my layering stuff. Believe or not, Kohls, Wal Mart & Target have UA knock offs for 10-15 bucks that works just the same as the $50 UA ones. (more mod money). Happy Shopping