Wear pair of pants and light shirt walking in regardless temperature down to 15 degrees. If you start sweating in your walk in, slow down. Don’t sweat. If you can’t help it, then don’t do your best to not sweat - do my best haha. If you still can’t avoid sweating, no matter what, then buy quality wicking layers that will pull the sweat from your skin, and spend money on quality gear that will pull the sweat from your base layers and transfer it through to the outside, or hold it in while still keeping you warm. Warning - they’re not cheap.
Get to your set, or a couple hundred yards downwind of your set, and get your body temperature down to cold. Not cool, not stop sweating, get cold. Then put all layers on lower body, and as much as you don’t want to carry up for upper body.
Then go slow, and confidently on your approach and climb. Don’t sweat. Don’t get anxious because you suck with your climbing method - this will make you sweat or go fast and sweat. When you think you’re going slow, go slower.
The key to all of this is knowing How much insulation and layers your body needs in 10* increments. Whatever the temp is, bring that. The other key is not sweating, and getting body temp down before you climb. Last key is either getting all sweat off of you before you layer up if you’re broke, or have layers that will pull it away from your body during hunt if you can afford it.
Mostly, go slow. It’s simple. If you want to hunt sub freezing temps for long periods of time, sitting still, you have to be dry.
I am not a fan at all of putting on clothes in a tree. I will add upper layers with no issue. But if I can dress completely, I do.
For what it’s worth I’m a hairy sweaty guy. But I can layer up with all layers, and drill/bolt my way up a tree, or one stick, and not sweat. Regardless of how much clothes I have on. It’s being efficient with my gear, and going very slow.