When I started trail running more seriously (i.e. all the time in all sorts of weather!) I slowly realised there was a gap in clothing options for various weather conditions. And then I discovered thir and the problem disappeared!
At Krayzie Kapers we use thir bands all the time. They have virtually completely replaced the wearing of hats/beanies and balaclava's are no more, we use them around our wrists for wiping sweat off, and as neck warmers they add a surprising amount of warmth to the whole upper body on extra cold days. There is almost no run we don't have a thir on or with us. We love them!