The Yakima is fishing fabulous. Predominant food sources include the
1) Salmon spawn ( specifically in the Upper Proper and the the Upper Flatlands
2) Baetis throughout the system... the Lower Canyon has seen some good to great risefests lately
3) Cranefly adults and the opportunistic trout eating them
4) Fall Cahill
Trout are creatures of habit. If you are fishing a dry fly in a hatch , generally the imitation needs to be ' drag free'. If getting a drag free drift is unattainable, then utilize the wet fly swing.
Positioning yourself according to what technique is being used, is critical. Angler position is a very important factor of fishing. Regardless of how accomplished a caster you are and how many specialty presentation casts you can perform, positioning yourself for the water you are going to fish is a primary technique. In fact depending on which type of presentation cast is going to be used in the attempt depends on what position you take to make the cast.
If you chose to fish a wet fly swing it is imperative that you are quartering downstream.
In both dry fly and nymph fishing "getting as close to the target" as the water type and situation allows is always recommended. Positioning (Quartering up, Quartering down, Direct 90 degrees, etc....) depends on where the target is and what type of cast is going to be used.
Just some food for thought!