For rainbows:
I am a bait fisher so here are a few ideas.

The almighty POWERBAIT, usually about 18" off the bottom (sometimes as much as 36"), cast it out and let it sit, if nothing happens within a moderate amount of time, reel in a little bit.

Another is to use a slip bobber and a worm, (this allows you to set the depth of your bait).
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Tight Lines