If I were forced to pick one fly pattern for the rest of my life - it would be a hares ear caddis. Very simple but very effective fly. Caddis live in most water systems but they really thrive in the Farmington River. Caddis can be found in the Farmington river all year round. They do vary in size and shape.  I tie these on barbless scud hooks and I typically pair them up with a slightly oversized slotted tungsten bead. My best success is with a size 16 in olive, and size 14 in tan.