I am a ned rig noob. BUT I have been catching tons of bass on it, and some really good ones to boot since I started using it.
I watched a ton of videos, read articles, etc... to get the basics down. It probably helps that I have been fishing 30+ years, and have been known to catch a few fish here and there too, but the learning curve was rather short for me...going from "lets see how to do this" to "well that's darn effective" in just a few hours.
What works best for me (so far) is a medium short cast....I can best describe it as, longer than a pitch to cover, but shorter than I would cast a moving bait...IE...about 25-30 feet away. I cast it either along deep grass lines in 7' to as much as 15' deep, or right into areas of sparse grass rock mix in depths ranging from the bank out to 15' as well. The 1/15th. oz head gets the most bites, the 1/10th gets a few, the 1/5th so far gets ZERO bites for me. I don't have any 1/20th...yet. I fish on a 7' M spinning rod w/10lb braid, and a 6lb FC leader, on a 2000 size reel. The rod is more like a ML than a M, and has a nice limber tip. As soon as I get a bite, it's a lift and reel set. The little hooks are buried every time, and I have yet to bend one or break a fish off. A lot of the fish I catch are 2-3 lbs, but I have caught a bunch of 4-5lbers on it so far, and other than a longer than normal battle because of the light leader and light wire hooks, have had zero issues so far getting them in the boat. The only bait I have used so far is the Finesse TRD's, and in my K.I.S.S. mind, they will be all I use until they stop working.
As soon as it sinks all the way to the bottom (a lot of bites are on the first fall), which takes a while the deeper you get, I either A.) point the rod right at the bait if there's a breeze, or B.) hold the rod parallel to the water at about the 9' o'clock position if it's dead calm. If the bait makes it to the bottom without getting bit, and with the rod held in either of the above mentioned positions, I simply give the reel 2-3 moderate paced cranks to lift it off the bottom, and then wait for it to glide back down, pausing a good while (8-10 seconds) to insure it's on the bottom, and repeat the 2-3 cranks/pause all the way back to the boat. I impart NO action to the bait with the rod tip, the most I will do is a shake/pop if it catches a piece of grass, or hangs on a rock. I would say, 80% of my bites come on the initial fall, and 20% come on the retrieve. The bites on the fall are 50-50 largemouth to smallmouth, and almost ALL the big fish I have caught on it, bite it on the first fall. The bites on the retrieve are about 80-20 smallmouth to largemouth, when it's a bass that bites it, and about a 50-50 ratio of bass to "other" species, with rock bass being the most common fish other than bass to bite it on the retrieve. It's kind of impressive on how much water you can cover with it in a short amount of time, even with having to "wait" for it.
IMHO the Ned rig is not "magic", as in it won't get bites when your not around fish, and jig head weight is SUPER SUPER critical, as in the the lighter the head you can use the more bites you will get. BUT it will get bites if your around fish that absolutely will not bite anything else. For me so far this year it is out fishing the drop shot, flick shake, shaky head, and other finesse/tuff bite techniques I lean on by a wide margin. The only thing close to keeping up with it so far this year is the Neko rig, which has produced less numbers than the Ned, but a higher % of big fish. IE, for every 3-5 lb fish I have caught on the Ned, I have caught double that on the Neko, but the Ned is producing it's big fish when I can't buy a bite on the Neko rig.