just throw it in and let it sink then pull it in a little bit and let it sink. I always fished it real slow and the fish will almost always hit it when it is sinking or just sitting on the bottom. try to keep as little slack in your line as possible and watch the line real close so you can detect strikes.
I don't think you can fish a Senko the wrong way. More often than not, the bait gets bit on the initial drop but I caught fish twitching it, hopping it off the bottom, dragging it along the bottom, and even doing a fast "walk the dog" on the surface. My best advice is to rig it with no weight. EH
The Senko is my "go to" lure under most conditions. I fish it slightly differient. I want to maximize the natural wiggle is has on the drop, so I let it fall on a slack line. If I don't get hit that way, I dead stick it for 10-15 seconds (drives me nuts-but pays off sometime). I have no luck with it at all with a current. I normally fish with a 5 incher, but if things get desperate, I have a supply of 4 inchers.