Trout, I assume you're talking the stocked variety, can be really stupid. They'll eat almost anything. I've had great luck using corn, hot-dog pieces, mini-marshmallows, commercial salmon egg baits, almost anything. For storebought bait it's hard to beat a crappie minnow (check laws) or a nice wiggly angleworm hooked through the center.
Once they become acclimated to life in the wild, creepy crawly things you can catch under rocks and logs in the water work extremely well. In season large grasshoppers are dynamite. They will also instinctively strike small spinners, spoons and minnow baits. When fish are running larger I like to run a small shad rap blue/silver trolled slow behind a canoe. When in doubt, cast a silver/white blue fox vibrax in the smallest size apropriate for your fish.
Think of them like little tiny smallmouth bass and you'll do just fine.