HF Red is still a good choice for powder. I've tried HF Black with very poor results. I now exclusively use HF red.
Make sure your tupperware has a 5 inside the triangle at the bottom. I've started using BB's, but I don't think it really makes much difference.
If you are getting poor coverage, use less powder and more boolits. My container is small, but I fill it 80% full of boolits. There is already a little powder left inside from the previous shake, but I sprinkle in just a little more. Too much powder, and you will not get the static you need, less is more.
Shake it vigourously. My tupperware fits in my hand, and I twist my wrist from side to side, flip the container over and shake some more. You should be shaking vigourously for more than a minute. If this is too much, use your tumbler to do it for you. I originally did it with the tumbler, but found I can hand shake and still get nice coverage. Mine look puffy when I pull them out of the tupperware, and I use a tweezers to tap off the excess powder.
I cut some AL panels to slide in my toaster oven, and cover them with Reynolds non-stick AL foil. I hold them in place with a little masking tape on the back side of the AL panel. I usually only use the AL foil twice before I dump it.
Another trick if you are still having trouble is to heat the boolits slightly before you powder coat. Have them just hot enough so you can barely stand holding it.
Don't expect 100% perfect coverage. If you look real close at mine you can see some imperfections:
I probably only have 95% coverage. I can make them with more coverage if I don't tap off the excess, but I don't feel this really matters. I have shot 10K of these in the last year, and the amazing thing is my guns only get cleaned once in a while now. I see very little dirt in my guns anymore. I have to clean my .22 every time I shoot, but not my .45's.
BTW I just made these today, and it's been raining all day. Oh, and I do size mine after PCing. This knocks off the lip at the bottom of them.