Over the last few seasons while fishing for silver salmon I have found good success in using a small spinner blade in front of my herring. Now, for some, going through the “trouble” of adding a blade to a herring rig for silvers would seem totally unnecessary. But it is pretty simple to do and as I have been experimenting with this setup, I have found blade-assisted herring well worth the little bit of extra effort.
Story by Dave Kaffke
The first thing you will notice when you put out a blade-assisted herring on the troll is that it looks killer. The little blade spinning in front of the rolling herring looks kind of like a bigger fish chasing a smaller fish. The next thing that I noticed is that as a whole, the bites on the blade-assisted baits are more aggressive, which has led to a higher bite-to-landed ratio. A real eye-opener was when we stopped the boat to fight and land a trio of silvers and began to mooch in place over the school and a blade rig that had no bait on it was taken with the rod in the holder and the rig about 10 feet down. 
Probably the most notable observation is that the fish tended to favor blade-assisted baits over non-assisted baits. When running four lines, two assisted and two unassisted, the assisted baits got hit at a 2-to-1 rate on three separate occasions. So, needless to say, I am convinced that adding blades to your bait rigs is a definite positive. If you decide to give it a try, here is what you will need to get started.
Blades: The blades I like are smaller blades in sizes 3 and 4. The blade I know as an FB blade in a size 3 works well. This blade is about the size of a number 2 French blade.
Clevis: The best clevis to use is a plastic quick-change clevis or GotZem plastic clevis. They will not fray the leader like a metal clevis. The quick-change variety of the plastic clevis gives you the ability to switch out blades but they can break in the netting process and blades will be lost. The GotZem clevis is made of a strong nylon that holds up well. 
Beads: For this application, 5- or 6mm round beads seem to be the best size to use. The number of beads will depend on the size of your blade. Be sure to put enough beads on the line so that the blade has plenty of freedom to spin in front of the herring.
If you give blade-assisted baits a try, keep in mind that you may have to adjust your herring a bit to get a good roll/spin combo. I have also had success running strips of bait and hoochies (plastic squid bodies) on this rig as well. There are a lot of colors available when it comes to blades out there and I would encourage you to try a variety of them and zero-in on the ones that work best for you.