I stumbled upon Shad by accident this past season. Got a buddy of mine that used to guide the Big D and he would rave about the Shad. I spend most of my time chasing Browns on the WB but decided to get to know the Main Stem this past season. I was a little late and started hitting the Main Stem around the beginning of June til around the middle of June.
I caught more Shad than I could shake a stick at. I caught a few on something akin to a "Shad Dart" but had the most success using black nymphs #14-#10.
To me these things were dumber than a box of rocks. They'd swim right up on you, right between your legs. They school up and mosey up and down a pool. I noticed that the first few times I saw them, they tended to hang under the surface quite a bit. Later on towards the middle of June they were right up near the surface, fins out of the water, very easy to see and fish to. I'd wait until I saw several heading towards me, cast out in front and start striping in once they got near.
One thing though: they are plankton eaters and have a very, very soft mouth. If you don't get them through the nose, you won't have one on for long.