One of the best methods for fishing caddis flies, especially when they are hatching is swinging a nymph or wet fly pattern. One of the earliest forms of fly fishing was to cast a wet fly quartering downstream and having the fly swing on a tight line across the current, this was and still is an effective fly fishing method. What I prefer to do now is to cast up and across stream and let my fly sink, I fish it dead drift like a nymph and then when it gets downstream of me, let it swing across the current. This makes the fly rise quite quickly up and across the current, much like the natural caddis flies do when they are emerging. Make three or four casts in the same general area and then take a few steps downstream and repeat. Strikes on this method are usually quite violent, as the fish is chasing a moving insect.
Caddis Flies
To prevent breaking off on the strike use a slip strike. This is where you keep a foot or so of slack line in your hand and release it when the fish strikes, this usually cushions the blow enough to prevent breaking. Many times people will see fish rising and actually jumping out of the water and yet fail to catch them, often times those fish are chasing caddis flies to the surface and it's their momentum that carries them to the surface and beyond, most times the swinging caddis method will fool these fish.