When I wacky rig worms I use different ones for different situations.
First I always use an octopus hook about 2/0.
When fishing in shallower water 1-8 feet, I use a Zoom Trick Worm. They are light, but cast just fine with a well-spooled spinning reel. Cast, let it sink for about 20 seconds. Make sure to keep some line tension to feel for hits. Then I reel in a little and let it flutter again.
For deeper water I use the same technique, but when fishing ledges and drop offs or deeper structure I fish Senko style baits wacky.
I always use natural colors such as Watermelon, Green Pumpkin, Pumpkin, Black and sometimes Junebug. I personally do not like shad-colored worms for wacky worming, but that's just me.