I hope yall dont mind me tooting my horn a moment for a change.
When it comes to soft jerkbaits I feel like I can say I am very proficient with them and will catch fish on them any season of the year. I use several different riggings for them though. I only use two soft jerkbaits: Super Flukes and Slug-Gos
First rigging that I use most commonly is weighless, texposed with a 2/0 hook. I dont normally like the bigger (heavier) 3/0 and 4/0 hooks. I like the slower fall the 2/0 gives. I also feel the 2/0 will also not impede the action as much as a heavier hook. This is not to say I will not use a bigger hook ever, I do at times, but most commonly I like the 2/0 hook and what it does for the baits.
There are times when I want to work the bait a bit faster than a weightless texposed rigging will allow. When that situation arises (like in the fall over submerged grass beds when the bass are feeding heavily on baitfish in the backs of creeks) I will put a swivel and then about a 12" - 18" leader between it and the bait. The swivel keeps the bait down without impeding it's action.
Other times i like to ensure that the bait will constantly break t he surface of the water. When Iw ant this to happen I will rig it texposed, weightless and rather than putting the hook in stright down the head of the bait I will enter the hook slightly back from the tip on the underside of the bait. This will cause the bait to sorta nose up when twitched and will force the bait to shoot to the surface. If you twitch it just right it will actually jump out of the water. I like to call this "The Breach" rigging. There are times when this rigging will catch fish that nothing else will even get a glance from.
As stated above, the most important part of softjerkbait fishing is the way the bait lays on the hook. If it is not perfectly straight... either re-rig it or throw it out because it will lose its erratic and unpredictable action.
Also, if you buy a bag of soft jerkbaits and realize that your tails are bent and they, themselves, are not perfectly straight, you have two choices. 1. throw out the ones that are bent (due to memory from not laying straight in the bag) or 2. heat up some water in a pot (dont get it boiling but get it pretty hot so that it is steaming) and hold your bait by the tail and lower it straight down into it. Let it sit in it a sec and then lift it out,s till holding the tail. Hold it up a few secs so it cools. That should remove the memory and straighten the bait out.
As far as senko's... I dont classify them as soft jerkbaits, though I know they can be fished in similiar ways and with those I do always use 3/0 to 4/0 hooks. But I mostly dead stick them.