Wacky rigging a 4" Yum dinger on a dropshot rig is "go-to" technique for me in the post spawn period, and anytime during the summer-late fall when the bite is tough and bass seem to be relating close to the bottom on the deep weed edge or isolated light cover out side the main grass beds. If they are suspended and the bite is tuff, a dinger on a wacky jig gets more bites than one on a drop shot for me, but the dropshot shines when they position closer to the bottom and seem to not be willing to bite jigs, t-rigs, other standard bottom contact presentations,etc....
I like a 3/8 oz sinker, as I am usually fishing this in 8-15 feet of water. It pulls the bait down quick, and I will get a lot of bites on the fall as they are not used to seeing a wacky rigged stick bait rocket to the bottom. Once the sinker hits the bottom, I let the dinger continue to "drift" down on slack line until it too is on the bottom............picture it this way.... Sinker and dinger go screaming down, sinker hits bottom and stops. Dinger pauses ever so slightly once the sinker hits, and then changes speed from a fast fall, to a painfully slow fall. Once the dinger is on the bottom I lift it up, but not moving the sinker. I would say almost 80% of my bites on this technique are on the short time between the fast fall, and the slow fall...........I often never know there is a fish on unless I see the line "tick" during the slow fall period, or when I feel pressure when I go to tighten the slack back up. If nothing grabs it on the first fall/pause/fall lift................I let the dinger fall slow in place again a couple more times without lifting the sinker off the bottom, and often get bit by a fish who has come over to see what is going on. After 3-4 times of doing this, and no bite............I reel in, and make another cast few feet away from the last and repeat the process all over again. I don't soak it too often, or move it around a great deal underwater....other than the little lift/fall routine.
I use my regular drop shot gear.
6'9" M/XF custom made spinning rod/Pflueger Pres. 30 size reel with 10lb braid and an 8lb fluoro leader
#2 VMC spinshot hook + 3/8's oz pencil shape dropshot sinker....I go down to 1/4" oz sometimes if I am staying in less than say 10 feet exclusively, or bump up to 1/2oz if I am fishing 15' + exclusively....but until I find out what depth they are preferring that day, I seem to stick with 3/8's as it's a good "general purpose" size..........sometimes changing sinker size and fall rate is a good way to mine a few extra bites out of an area that you have already caught a few good fish out of. I generally keep the bait 12" or so above the sinker.........ALL THE TIME.
Color of the bait seems to matter little.........but I like black and blue on a cloudy day if the water is stained, green pumpkin/chart tail on sunny days in stained water, plain green pumpkin in clear water, and some kind of watermelon on really sunny days in extremely clear water. White seems to be deadly in the late summer/early fall and will out fish the other colors handily no matter what the water/sky conditions.