Once I'm up the tree & cooled down (if I got heated up during the climb,) I take my good 'ol Zippo, fire her up, burn the end of the cork, let her cool a minute, then smear the charred end on my face. Repeat until I get the coverage I want. Easy Peasy!
Also, make sure you put a horizontal line under each eye-if it's a sunny day, that helps in reducing the glare (just like my old high school football days!)
...Just make sure you get a REAL cork from your
Real Boss's wine bottle-the rubber ones don't work so good...