Hopper-dropper is a great way to fish many of our eastern slopes rivers. Just add on a nymph about one or two sizes smaller than the dry fly about 2 to 2.5 feet below the dry fly. Tie on a length of appropriate tippet to the curve of the dry fly and then secure the nymph to the other end of the tippet. You certainly have the best of both the dry fly and nymph fly fishing covered. It is a bit tougher to cast but you double your chances at a hook up!
The above example is a size 10 foam chernobyl with a size 14 flashback dropper.