Puffer vests are back. Not that they went anywhere, exactly, but expect to see them all over this season. Scratch that: Expect to wear them all over this season. Dress it up or dress it down, the puffer is the ultimate casual utility layer. The sleeveless puffer is usually filled with down or feathers or some combination of the two, and while designers seem to have recognised the practicality in packing on some heft to combat the cold, they also know you don’t want to look bulky. So the new breed of this wintertime staple has arrived with a trimmer,…