Have recently been thinking about what to do with my .5 oz cf and just had the idea to make a hat cover. The idea is... I assume goretex hats would be much hotter and sweatier, and heavier than non waterproof hats. When it rains though, having a waterproof hat means you can ditch a hood and have a much better time (better visibility, airflow movement etc).
I thus plan on making a hat cover maybe with a velcro attachment at the top and also attachment points around the brim. I reckon this would only weigh 20 or so grams and would be pretty darn handy.
Has anyone done this before? If so does anyone have any tips?