I wear UA cold gear, the leggings, shirt, hoodie, and liner gloves. I put cabelas extreme cold base layer over it. I use a thin polypro sock for moisture wicking with an extreme cold thick wool sock over it. The UA hoodie is surprisingly nice, I used to use a thick fleece neck gaiter, then found the cold gear hoodie to be equally as warm, with nowhere near the bulk. I just bought another in white for winter hunting.
I'm a hand caller, so I don't like having a huge glove on my hands, the cold gear liner glove is tight fitting, but nowhere near warm enough for my temps, so I put a wool glove over it, these have the fingertips cutout to allow me better feel on my calls and trigger. I will also wear a hand muff hand warmer to put my hands in when not calling, and also to store and keep extra calls warm so they wont freeze up.
I don't use pac boots, thought about it, but they are stiff, and if a guy has to walk a good distance in to his stand they wouldn't be fun. So I bought Cabelas 1400 still hunters, still a very warm boot, but a hunting boot, meaning they wont have that super thick sole, they will be a better boot for walking, plenty warm, as you aren't sitting on stand for that long anyways. I am usually sitting for longer than most, I like to sit on stands for an hour+
I really believe in having a good base layer, if for nothing else, it is for its moisture wicking abilities, fact is, you are walking, then sitting, if you sweat while you walk and that moisture sits on your skin, you will freeze when you're sitting. A good base layer, or in my case, two base layers, can help solve that.
I was out sighting in my new gun the past few days, at times it was -10F and colder, you gotta dress smart, deciding to stack old T's and old sweaters on for warmth may save you some dough, but it adds a lot of bulk, making shooting more difficult, it also holds moisture.
Do things right, spend the $$ now, be comfortable, and you'll want to hunt more, go the other route and you may find yourself quickly deciding winter hunting isn't for you, and with coyotes moving more, you're missing out on what many consider to be the best time to hunt coyotes.