Suggests many critters, from emerging mayflies to caddis pupae to egg-laying caddis. They can be effective when there is no hatch in progress. Soft Hackles are particularly productive on caddis-rich rivers.
To tie a Hares Ear Soft Hackle, skip the thorax and use Haretron dubbing for the body. Weighting with a few turns of very thin lead will help it break through the surface tension. A beadhead can do the same thing, and it's easier.
To imitate caddis, chose abdomen colors that match the natural insects.
How to Fish
Use a floating line and a wet-fly swing. One good strategy is to start fishing with about 20 feet of line. Quarter your cast downstream, throw in an upstream mend to slow the fly, and let it swing. When the fly is straight below you, let it hang for a few seconds. Then cast again with about three more feet of line. Keep doing this until you're at the limit of your casting, then walk downstream 30 feet and do it all again. It's kind of a stupid way to fish, but it can catch a lot of trout.
You can also use a Soft Hackle as a dropper off a dry fly, or use the shallow nymph tactic.
HOOK: 5262, 3761, 900BL, or 200R, sizes 10-18
THREAD: To match body
ABDOMEN: Floss or Haretron
LEGS: Gray or brown partridge tied so fibers extend past hook point