This time of the season everyone loves to fish big stonefly and salmon fly imitations. When I say big, I'm taking about size #6 and #8 bugs. In my experience, these larger flies work well in the early part of the hatch. However, as the hatch moves into the later stages, Deschutes trout get pretty dang wise to the old #8 Chubby Chernobyl. You'll still get rises but you'll notice your hooking and landing ratios go way down... Especially with Walter. The big fish get educated easily! When you get refusals on the big bugs or you see a lot of what I call, "false rises" -the fish will roll on the fly but won't actually eat it, its time to go to plan "B".
Downsize Your Fly- Try fishing a #10 or even #12 golden stonefly adult. It's hard to find these in fly shops so you may have to tie your own.
Fish a Yellow Sally Dry as a Dropper- One very deadly technique when the fish get smart is to fish my Yellow Sally dry as a dropper. Just tie an 18" dropper of the bend of your salmon fly. You'll be amazed how many fish will go for the smaller offering.
Twitch Your Bug- Some days the fish want the fly on a perfect dead drift. Other days, adding a little movement can get the trout amped. Watch a real stonefly skitter across the surface and try to immatate the movement using subtle rod tip wiggles.
Fish Something Other Than a Chubby- There's no doubt the Chubby Chernoyble is a great fly and finds it's share of trout. However, when everyone on the creek is chucking the same bug, the effectiveness of any fly goes tits up. I always look at the bins at fly shops to see what fly is "hot"... Then I fish something completely different.
Be Stealthy! The trout go on high alert when river traffic picks up. Anything out of the ordinary will put them down and the show is over. Wear natural colored clothing to conciel your presence. Try to fish like a heron... Be a trout trout ninja.