there is nothing like a fish taking a dry. And it gets better as the sizes of the fish increase.
We started out today with soft hackles which can look like a variety of emerging bugs or other swap food. I hooked a couple on them, but once i saw the little caddis coming off and the swallows working the lake, i switched to a #16 or so Elk Hair Caddis(blk) and just cast to an area of rising fish. Sometimes it sat on the surface for a minute before a fish would hit, other times it was instantaneous. What also was good, was stripping it very slowly to make a little ripple around the fly and this initiated a few strikes as well.
I then switched to a parachute adams in about a 14 as i saw some large mayflies coming off. This worked well, but once i put on the merger the fishing really took off. stripping it like a bug trying to get away caused some great strikes.
not sure if you know this, but when you are looking at rising fish, splashy rises = caddis hatch.... graceful or slow rises = mayfly hatch.