I have to diagree with making long casts with a Senko and missing fish. I almost never miss a fish with a senko, unless they are just way to small. But 4" I use a 2/0 offset worm hook, 5" a 4/0 or 5/0, 6" a 5/0 or maybe a 7/0. But with wacky rigging I use some hooks that a friend brought me from Japan that have a weed guard...awesome!

You can fish it like a worm on the bottom, or like a slow soft jerk bait. You just have to let the fish tell you how they want it. Just experiment a little to find what works best for you.