The simplest and easiest way I know to troll for trout is with half a night crawler threaded over a #4 or #2 bait holder hook (the kind with barbs on the shank).
Use a worm threader and leave about 3/8" of the pointy end of the worm hanging past the hook. That means poking the worm threader into the worm in at that point and coming out the cut end. This makes it very hard for the fish to get the worm without also taking the hook. It is not unusual to catch 3 or more fish on the same half worm. By the way use the back half of the worm first. The front half will survive longer if you don't find it right away in the bait box the next time you bait up.
Use a 3 to 4 foot (4 or 6 pound) leader connected to a 1/4 oz to 1 oz chain bead weight.....either a banana type of the keel design that is connected to your main line. Obviously the heavier the weight the deeper the rig will go. Thost weight designs with the chain beads on each end will prevent line twist on your main line as the worm has a tendency to spin; especially if it is not threaded on straight.
Let out a minimum of 50 feet of line and troll between 1.5 and 2.5 mph. I usually go back 60 to 75 feet and with 3/8 oz. weight the rig will run about 5 to 10 feet deep in the water. The rods are held out perpendicular to the side of the boat. Normally I prefer to troll along the shore in 15 to 30 feet of water.
Now when you get a hit but no hook up, immediately drop the tip of the rod straight back to the rear of the boat. A high percentage of the time the fish will circle back and hit again for the hook up. By dropping back you allow the bait to stay close to where the fish hit it the first time and the usually try again. Just doing that will greatly increase your catch.
This method will work with most lures and flies like a Wooly Bugger also. As mentioned, needle fish are good and if you use spinners the chain bead weight will all but eliminate line twist.
In places with weeds near the surface like the South End of Diamond Lake, you can use a light weight and troll with the Wooly Bugger over the weeds just under the surface of the water. Go much faster than you might think if reasonable and at least 100 feet behind the boat. The fish will come out of the weeds to hit your rig.
As usual morning and evening are best for fishing along the shore line.
Now you can use flashers or dodgers in a similar manner, putting any weight you need in front of the flashers but reduce the length of the leader to 12 to 18". But why deal with dragging all that gear and lose the fun of fighting the fish when you don't need to. I do as well or better than most people dragging hardware.
If the fish are deep, this method will work using a down rigger or other deep fishing gear but as you go deeper the flashing hardware does seem to attract the fish better than the stripped down method I have described above.