Stalking big stillwater trout. I have done lots of it.
Two lines to use are a floater dyed to match the colour of the bottom and a clear intermediate. Fluorocarbon about 8 lbs makes up the leader. A rod of about 9 to 91/2 foot weight 6/7 is fine. Avoid long casting brute sticks here, they are awful for play big fish (see Playing big fish in coarse section)
Use ONE fly only. I have done very well using weighted damsel nymphs, GRHE nymphs and Montana variants.
Dress in camo gear, get a good set of polariods and spend most of your time watching the water, not casting. The whole idea is to ambush your trout. Big rainbows often have a beat. If you lay on your stomach they will cone right up to you in the margins. Cast out in the area where the fish will pass by and wait. When the fish gets in line with your fly start your retrieve. Most times the trout will have it like a shot and then prepare for fireworks.
I like to get the line back on the reel as quickly as possible and play the fish off the reel. One of those wide arbour reels work very well. Don't be afraid to give the fish some heavy stick when playing it.
Good Luck
