Hats
In winter I use the old wool Navy Watch hats so that I can get my
eye to the viewfinder. In summer I either use a baseball cap which I
wear backward when photographing or a big (ventilated) loose
floppy hat that protects my ears from too much sun. Best of all I
wear those synthetic beanies, which have no visor. Patagonia sells
them.
Mosquito Netting - As the season grows longer and I still want to
get into the deeper danker woods, I carry mosquito netting that
goes under my hat and covers my face and neck. Any sports store
has them for almost nothing.