From my experience the Female patterns work the best. This season I've been using #24 females using biot bodies and fine dubbed thoraxes. I use both spinners and CDC emerger patterns. I did use some #20 male trico's earlier in the season, but smaller does seem to be better with this hatch. Funny story, two weeks ago I fished the E. Branch of the Croton durign the morning Trico hatch. The conditions were not ideal, and the hatch was sparse. I got a little impatient between the dun and spinner fall and started spot casting to small sunnies. They all rejected the trico. Some time passes, and the sunny's stack up in a line right in front of me. I cast to them a few times, and they all rejected the fly. I started to wonder if the pattern was too big, or if I was getting drag, basically questioning the situation. A few minutes passed, and off to the far side of the line, I saw a sleeker, yellowish sillhoutte gently holding position. Knowing darn well what that profile was, I cast immediately in front of sillhoutte, and the water exploded. I fought that brown for what seemed like 10 minutes. My point... Funny things happen during the trico hatch. Small sunfish rejected a fly, which they normally would swarm and inhale, and an older holdover brown viciuosly inhaled it. Make sure you have small, buggy looking tricos. I highly recomend biot and cdc. and if it's not working, change out the fly (caddis, midge, rusty spinner etc) or tie on smaller tippet. Just my experience, diffrent conditions will dictate diffrent tactics.