Yup, first pick yourself a good spot, somewhere you might be if you were a fish, or just where other people you have seen caught fish.
Build a good rod holder, if dont already have one. Go ahead and stick with your 12 pound test on the mainline and go up little to ten on the leader.
It sounds like your plunking so go ahead and get a three way swivel, tie your mainline to the top eyelet of the swivel, your leader to one of the other eyelets, then on the other you are going to use a dropper, I like about 10 or 12 inches, this dropper line should be eight pound test, lighter then your mainline and leader, tie your sinker on next, if using pyramid sinkers put a snap swivel on the end of the dropper line and snap weight on also you can do this with round ball weights, if you are using tear drops, tie them directly to line.
As far as rigging goes i would depending on condition, but this is pretty versatile so itll probably work. First start with two #1 or #1/0 hooks, tie a double hook snell knot, with about an inch and a half between the hooks.The leader should be about four or five feet no shorter, not much longer. After hooks are tied slide a bead down to hooks, then slide #8 or #10 pink pearl spinglo with the white wings down to bead, the bead will make the spinglo spin well and protect your knot, also instead of the spinglo if you can find a birdie drifter or glow go in same color try that.
The important part is the bait, i like to use live sandshrimp, but cured will work. The key is to rig them on your hook so that when you put the finished product in the water to look at it, only your spinglo should be spinning not your whole bait and everything, it should be very smooth and looking tasty. I dont know If i can explain it, but Ill try. First hold the sandshrimp tailfirst, curl about a quarter of the tail underneath the other part of the tail, then stick your top hook, the one closest to your swivel square through both pieces of the tail, so it hangs on, then turn bottom hook upside down, put through chest cavity and make it come out between its tentacles or mouth area, kind of like texas riggin a plastic worm for bass, except leave the hook exsposed. Itll take a little practice, but this will make it hang straight.
Then the next important thing is casting, whenever casting watch to make sure it doesnt tangle in mid air, a underhand lob is often better than a hard overhand cast, itll keep you bait looking better to, then just let it rest in a good spot, and wait, keep a tight line.
Also eggs will work too, put them on the top hook, using your bottom as a stinger.
Hope that helps.
P.S. If in the right spot, experiment with side planer and plug, side planer comes with instructions, sometimes will outish plunking in a good plunking hole. Nice thing is it`ll go in a rod holder and all you have to do once out there is wait or work it around the hole.