If you can’t get a bite, try fishing static.
Sometimes no matter what flies you try, what depth you fish, or what speed of retrieve you use, you just can’t persuade a trout to take a moving fly. This seems to be especially common when it’s really warm or really cold.
If you struggle to get a bite, it’s always worth trying to fish your flies completely static to see if this attracts any attention.
It’s always my son-in-law’s first tactic if he can’t get a bite. He’ll snip off the old fly, tie on a blob, squirmy wormy, egg fly attach a strike indicator a few feet up the line, and cast it out.
Sometimes it’s just the thing to induce a take. It also means you can have a sit-down and rest your arm or like me not haveing great knees a seat comes in very handy lol.