Anglers instinct is what tells you which kind of water looks fishy, guides you on were your cast goes and tells you when to set the hook or change flies. Instincts to a spey angler develop differently then they do to a nymph fisherman. Water that swims a fly well on a sink tip may not fish well with nymphs at all.
We have so many new rods, lines, flies, and sink tips that catching migratory fish on the classic down and across presentation is more successful then ever. With that said the most effective tool in your arsenal is your mind set. So many steelhead and salmon anglers have earned their skills and knowledge about catching these fish through nymphing techniques. We learn to develop instincts and reactions to the type of angling that we choose. Often the transition from nymphing to swinging is an easy adjustment for your skill sets such as casting and mending but the transition in instinct can be hard to overcome. Here are some of the common problem spots.
In nymph fishing we are trying to to get our flies on or very close to the bottom, being deep is a primary concern, when covering the water with a swung fly depth is my secondary concern. A proper and smooth presentation of the fly with the fly leading the coarse down river in front of the leader and line is more important than depth. I do want my flies near the bottom when possible however don't want them beating on the rocks.
Good fly water for both approaches can differ drastically. Swinging flies with spey rods effectiveness comes from its ability to cover huge amounts of water. When swinging a run I will start at the very top of the possible holding water cast down and across to the far side of the run, let the fly swing to a hang down and rest their for a few second and then step down stream about 5 feet and do it again. If I am fishing from a boat with 2 anglers I will step about 10 feet between each cast. Nymph fishing's effectiveness comes from being able to deliver your flies to very specific spots often with repeated presentations to the same location. Because of these differences we approach the river with a much different view of the water that we want to cover. When swinging I would cover a 100 yard run in the same time that I would fish a 40 foot long seem with an indicator rig.
Setting the hook. This is a big one. A nymph angler is wired to set the hook to the slightest pause. A spey angler typically doesn't set the hook until they feel a full take with the weight of the fish putting the rod into a bend. Steelhead take a swung fly in so many different ways that we simply couldn't cover all of them here, so lets cover some basic or common strikes. The pull is not a take at all but simply the fish letting you know that their paying attention. Typically your fly is swinging on a tight line and you feel a sudden tug, some of these are subtle some aren't. It may be hard to resist but don't lift the rod these. Most of the time when you set the hook on a pull the fish won't come back. If you let this pull go often the fish will grab the fly hard a few seconds later or on the next pass. When the fish does come back for a full on take and you can feel the weight of the fish simply lift the rod into fighting position and go to work.
So the next time that you go to water to swing for you fish take all your favorite flies, rods reels, lines and the right set of instincts to match. I believe that this alone can make the biggest difference in a successful trip.