Way to go Dragon. Here's some flies 101. Always take some time and observe the insects in the air and the water. I am guessin those flies you found around your face were Chironomid flies/adults. The red things in the fishes stomachs would have been Bloodworms (Chiromonid larva), if you had looked closely you would probably have seen mases of them floating in the water column. Here's the trick throw out all the crapp the know-it-alls pitch and follow this simple formula. Size, shape, color; in that order. In over 35 years of fly fishing I have found that fish generaly focus on the silhouette, if you get that right, that 90% of it. As for the lake in you picture I'm guessin Wood or Weaver.
Hey "Keep that fly in the water" That where the fish are.