For the ecologically minded, good old mild-temperature water is one option, but for those needing an industrial clean, Nikwax has a host of tried-and-true additives and soaps that clean, condition and re-waterproof literally any type of layer. Proper care and regular washing ensures ski clothes’ longevity—just be sure to read washing and drying instructions carefully.
In general, avoid heated dry cycles for base- and midlayers—they can shrink, pill or even melt. For outerwear, some heat in the dryer is essential for re-upping waterproofing. And for puffies, keep them puffy by adding a tennis ball or two into the tumble-dry cycle.