When going after brookies or rainbow, I usually put my set line in 2-5ft of water, just a few inches below the ice. They have a tendency to constantly be on the move, following the shore or contour. they will sometimes do laps around certain areas. If there’s any sort of spring or inlet, those are prime spots to fish, but be very careful where you step. Any structures like submerged trees and weeds are also attractors.
Forget the minnows. For traps/dead sticks, I usually use a chunk of nightcrawler. Then I’ll jig close by with something flashy or a rattle spoon tipped with some waxworms or earthworm. Sometimes I’ll just travel between my traps and jig along the way or next to them as trout are curious. But If there’s a nearby drop off or deep weedline I’ll jig there while watching the flags near shore.
Trout tend to be aggressive under the ice and move in groups, but they will hit and spit often. They tend to slash at bait, and will circle back around again several times before you get the hook in them. On set lines they often steal the bait or chew up a minnow without tripping the flag. When you get a flag, get to it quickly but quietly, and set the hook fast before they spit/swallow it. If you get a flag but no fish, jig in that hole. There’s prob more fish there or it hasn’t gone far and can be lured back.
