Fish Can't Resist This Foam Dry Fly — Fly Tying in 60 Seconds There are times during a bug hatch where fish get super keyed in on one type of fly. The Twin Territory Emerger is a great dry fly emerger pattern to tie on when fish are picky. It could imitate both midge and mayfly emergers. We would recommend tying them in sizes 16 and 18. In this 60 second mini fly tying tutorial, we will walk you through how to tie this fly fishing fly step-by-step. Grab your fly tying vise, tools, and materials.