The fillet is placed with the skin side toward the lure. Secure the fillet with elastic sewing thread. I wrap my plugs the evening before I use them and I keep them in clean plastic boxes. I won't fish a plug more than an hour. After an hour in the water most of the smell has washed off.
Plugs work best when they are wiggling rhythmically.
If the plug is shaking wildly, it will spook the fish. To avoid overactive plugs, adjust your boat speed or work slower moving water. In the past few years the cut-plug herring has been Clancy's favorite fish producers. Clancy has spent scores of days on the water experimenting with herring. I have a brine recipe of my own.