Here's what to look for when buying a good duvet: The shell should be a high enough thread count to prevent noisy crunching. The softer the shell, the lighter and more breathable the duvet will be. The construction should be baffle box (not channels) to prevent clumping. Choose pure white goose down. The amount of down fill (in ounces) is a personal preference. If you are typically hot when you sleep, choose a light or ultra light weight. If you're usually cold, you may prefer the regular weight.