When evaluating winter outerwear, focus on insulation material, shell durability, and weatherproofing. For insulation, check the Fill Power (FP) for down (600+ is premium) or the GSM (Grams per Square Meter) for synthetic padding (150-200 GSM for extreme cold). The outer shell should ideally be made of high-density Nylon or Polyester with a Durable Water Repellent (DWR) coating. Ensure the Waterproof Rating is at least 5,000mm to 10,000mm for snowy conditions, and verify that seam sealing (critically taped or fully taped) is applied to prevent moisture leakage.