Rob,
Sorry have cocked up and posted this twice as was timed out and panicked at having lost my reply!!
We carry one rod each and adapt the set up to suit. Having said that 95% of our fishing involves targeting what we think are 'large' fish of 2lbs +. Having said that it is relatively easy to discern this if the fishes head breaks the surface to take a dun or something sitting on top of the water. In April on our first trip there were Black Gnats coming down and they do sit on the surface albeit with a far lower profile. We suspected that the fish were on these but their heads were not showing and I recall targeting one with Paul watching and this ended up as a 24" fish. We had no idea it was this large,we could tell it was substantial as the rise form was a fair size but we both thought it was a 2lb-3lb fish tops. I have digressed from your question.
Set up is a 9' rod either 4 or 5wt depending on the wind and leaders anywhere between 12' (very windy)-16' (no wind) ending in 5X (4.9lbs) or 4X (6lbs) which will vary depending on fly size and perceived size of fish. I maintain that with a well tied knot no fish is going to break a 4.9lbs leader on snag free run (though I think that this happened to Ben so shows what I know). On the previous trip I was broken by the largest Trout I have ever hooked,I saw it jump 4 times and reckon it was over 7lbs but it ran me round a rock and frayed the leader against a rock-nowt you can do about that!
The flies we have had most success with have been Paraduns,Paragnats,cdc and Klinkhamers.
We do a lot of walking,sitting and looking. Pauls Trout he got on Monday of 4lb 7oz I guess many people would not even have spotted. He was not sure it was even a rise but went down to close to where he saw it,waited 20 minutes before it came up again,had a few casts over it,the last of which was dumped down over the fish by a gust. He thought that that was it all over but again waited over 20 mins and it did come up again by which time he had changed fly and got it. So he was successful by good observation and sheer perseverance and patience that not many have. Okay his presentational skills are of the very highest order too! However many of these Trout allow a pretty close approach as the Don is usually of good depth and flow so you can get close(2-3 rod lengths usually) without scaring them.
If things are very quiet and we get a bit bored then Paul is first to change to weighted nymph on point + 2 spiders and prospecting down and across to cover a lot of water(not on a tight line like a salmon fisher though). The rod is held high so there is a bow of line to watch for a take and the fish does not feel a lot of resistance, resulting in more hook ups.
However most of our big Trout are taken on dries and are targetted. We rarely 'fish the water' as this usually results in smaller fish. Obviously once you have a biggie on your sites do not rush things,check knots,watch the rise pattern etc. Many fish are difficult in that they do not hold station (due to the fact that the hatches/falls are not usually that heavy) and traverse a bit so you have to be careful not to line them.Wait with the correct amount of line out,fly in hand and when he comes up try and get your fly over him after a couple of seconds. This can take time!! That massive fish that ran me round a rock took over 2 hours to hook (drag was awful too). If your fly drags a few times and you think he may have seen it it may be a good idea to change (but we have taken fish on flys that they have seen drag previously). Finally these big fish rise slowly and turn down so give them a bit of time before striking.....only experience and missed fish will hone this for you!
It is not everyones style of fishing and you have to be very single minded,but hey its what we travel 700+ miles each round trip for!!
Good luck Rob at Monymusk. Wish it was on my way home. Let us know of any success you have. Reckon that you should be on the water from 9:30pm at the moment. As dusk falls you can get really close. Make sure you have some flys tied with a fluorescent yellow post.
Oh yes we do not do any nymph fishing but that is not to say that it would not be successful but generally if there is a big fish out on station feeding (as opposed to tucked under the bank or a weedbed 'resting') and we have seen him rise we will approach with a dry fly
Hope that this helps,
Richard