It depends on where I'm fishing as to what works. At Lake Simtustus it's green wooly bugger with a soft hackle trailer. The Crooked for me it's prince nymphs or pheasant tail nymph. During the bug hatch on the Deschutes it dry fly time with a stimulator or similar fly. So many rivers so many flies.
The San Juan worm now there is a fly I can tie, and yes it can be effective.