A lot of this is personal preference... there are some basics though. I like Firstlite... and one of the reasons I like Firstlite is that I prefer Nylon over Polyester. Base layer... boxer briefs, darn tough socks and T-shirt, beanie for the head, glove liner and neck gaitor should always be merino wool (or alpaca if you can afford it). Mid layer for me is always merino wool as well as it still contacts the skin on the legs and arms... this would generally be called long johns. Then you have the outer later... which can be Polyester or Nylon. Polyester absorbs oil and Nylon absorbs water. After a few days in the field you will have oily skin... it's just the way we humans are... your skin secretes oil and oil is good for the skin... keeps it from drying out... but it maintains human scent. This also makes Polyester difficult to clean... ever take off a polyester tank top after going to the gym and throw it in the wash... put it on and it smells good... then after your body heat warms it up... smells like you just worked out in it?! Nylon absorbs water... does not hold human scent like most polyesters... don't get me wrong... the newer, more expensive polyesters are better at minimizing scent, but Nylon is still better at it. Polyester is a better insulator though... so a Nylon coat with polyester insulation is good. Better yet... a Nylon rip stop coat with treated down... will keep you very warm. Add a heated vest under that and I can sit in the stand all day long.