A fast hookset is very important when fishing the jig. I dont know what kind of water you are fishing but a 12 lb leader seems vey light to me especially if you are fishing wood or brush. When I use the braid to Fluro set up, I am almost always using a 17 lb leader and never go below 14.
Above all else, just stick with it. With a little practice you will be lipping those things left and right.