I will fish the brushpile a few minutes regardless of seeing fish on the depthfinder. I really like to see bait balls close to the brushpiles but I catch some when they aren't around too.
My favorite technique is as soon as I can reach my shallow water brushpiles, (8 to 10 FOW), I like to pitch my jig up past the pile and let it pendulum back towards the boat. I normally catch the biggest crappie that I'm going to catch there doing this.
Todd Huckabee says that anything shallower than 10 feet he likes to pitch a jig and cork to so he can stay back and not spook fish.
I still like to get up there and jig but it doesn't take long to spook the bigger ones off and all you catch are the dinks.