I live in Colorado so naturally I catch alot of trout, especially rainbow, and what I've found to be the best bait is actually just simple nightcrawlers. I personally use a gang hook to hook the nightcrawler, which You can buy at some places but I usually just tie my own gang hooks. Although I've also had alot of luck with hooking them "wacky style" as well.
However for any type of trout, I also really like spinning lures. Personally My favorites are the Mepps Aglia, the comet mino, and the black Fury. But I've had alot of luck with virtually any mepps or panther martin spinning lures.
One last really great way to catch trout which I'm sure you've probably been told about is sitting powerbait or salmon eggs. generally I prefer a powerbait or salmon eggs with glitter in them, It may sound silly but it really seems to help! When I fish usually I bring two rods (sometimes more) and i'll have one rod strung with a powerbait rig and I literally just cast it out and leave it there while I cast and retrieve with my second rod. The only thing I'll say about that though is to make sure you pay attention to your powerbait rod. Some guys wont notice their line getting hit without some sort of bell on the end of their rod.
A good rule of thumb when fishing with powerbait is to throw it out, wait for 30 minutes or so and if nothing has happened, pull it in and check the bait and repeat.
hope this helped a little!