I use Yamamoto brand pink worms in either 3 or 4 inch size. Others use Berkley worms, some have embedded scent, and there are lots of other brands with different tail configurations, etc. I havent done enough testing to determine that one brand works better than another.

I thread a #2 hook thru about 2/3 of the length of the worm so as to leave a "tail". I always put a float in front of the worm and most often use a little scent on the float -- anise, shrimp, egg, etc.