Flossing is like drift fishing with a very long(maybe 6 feet) leader and letting the line flow into the fishes mouth, then as you retrieve it, the hook slides into the corner of the mouth. Your gonna ise a small corcky to float your line off the bottom and put it at fish level. Also the yarn will get caught up in the fishes teeth and give you time to set the hook. Thats the idea at least. Lots of fish will hit this set-up so you might as well put on a small egg cluster too.
Plunking is like bait fishing. Cast it, tighten your line and wait. I would suggest using a spin-n-glo and bait if your plunking..