To set up a salmon flasher, start by attaching it to your fishing line about 24-36 inches above the lure. Next, tie a swivel to the end of the flasher and connect your leader and lure to the swivel. Make sure to choose a flasher color that matches the water conditions and try different patterns until you find what works best. When trolling, vary your speed and depth to attract the salmon. Adjust the flasher's position on the line to achieve the desired action and rotation. Experiment with different flasher lengths and leader lengths until you find the optimal setup for attracting salmon. Finally, cast your line and start reeling in slowly to attract and entice the salmon using the flasher's enticing movements.