Those two articles will tell you everything you need to know about blackfishing and the advice from Waza is spot on!
Balance you float right, mine has only 1.5cm of stem showing.
Get yourself some green weed and/or cabbage, you'll get more blackfish on weed than on other baits.
Mix up berley with the same weed as your bait with a couple of handfuls chopped fine per 10L sand.
My leader is 6lb FC Rock at .205mm.
Then vary your depth till you start getting bites!
There is also a theory that if you can see the fish, you won't get a bite . . .
Good luck in your blackfishing journey!
stu.