How many layers and even how warm of clothing you wear will depend a lot on how you hunt, how much you move, etc. If you're sitting in a stand, you'll want warmer clothing. If you're hiking a ways to get to that stand, you'll want layers that you can pack in cause you'll burn up if you wear all that gear while hiking. You'll also want more (warmer) clothing if you're sitting in a treestand versus some type of enclosed ground blind or enclosed blind, especially if you have some kind of heater going (say like when people ice fish). My preference is spot and stalk hunting so I prefer lighter layers that I can shed and carry in a pack as needed. Your type of hunting might be totally different from anything I've posted so it's really going to depend on how you hunt and how warm or cold you like it.