Clothes can contribute, or detract, from your ability to make use of the second and third basic principles for successful dry fly fishing, observation and stealth. Let us begin at the top with the head. Starting with the eyes. Your polarised spectacles will be vital for fish spotting and protection from a wayward cast. Mine are a very old pair of Optix Cormorants that are a pale grey and work well even in dim light. Whatever sort you prefer, you can optimise the effectiveness of your polarised spectacles by wearing a hat with a full brim to shade them from behind as well as above. This will let you see more clearly, in the same way a lens hood often improves the quality of photographs.
On a recent comment, Warren kindly put a link to a photograph he took that shows two pretty reasonable examples of good shape and good colours of hat to go for.
John's hat is a darker greenish olive of rabbit fur felt. This is pretty good in cool weather and is okay in light rain too. Mine is the khaki one in canvas duck that came from Orvis. It needed modifying by covering the silly leather hat band with a strip of material, webbing in my case, so damp flies can be stuck into it. That way they do not bring water into the fly boxes and rust all that hard work away...
This hat has been superceded at Orvis by the River Guide Hat and sports a reinforced brim so you can shape it. My advice would be to keep it shaped like an upside down dish to get the maximum shading effect for your polarised spec's.
You may like to obtain several hats to cope with the vagaries of weather, a dark green or brown straw hat maybe, for boiling hot days in summer; one of canvas duck for most days and maybe something waterproof, or at least water resistant for rainy days. Just make sure that whatever you get, your hats should shade the back of your polaroids as well as the top and, most importantly, they are always as drab as you can get.
Well that's your head taken care of. Next time trousers and how they also contribute to observation and stealth!
Regular Rod