This one is fussy, maybe it’s the cultivar; Kyokko Yatsabusa, or just the fact it’s a corkbark black pine. I pruned and wired it out in 2014, and it’s taken all of the last 4 growing seasons to strengthen to a point where light pruning was an option again. An aggressive fungicide regime has all but eradicated needle cast, and the black aphids draining an occasional needle aren’t decimating it.
I do not do summer candle-cutting on this tree, but instead, allow it to grow, and then thin buds and pull needles in the fall. Here is the mid summer shot:
And after simply pulling downward-facing needles, and thinning some congested shoots, and a few strands of #14 wire to coax a few 2-year old shoots into position, here is the result:
If the upper right area continues to fill in, and I can get the first left branch pulled down just a few more degrees, I think I’ll be satisfied to just feed and water it, and spend a couple hours each fall tidying it up.
Nebari Bonsai 
what soil?
Lava, pumice, akadama, 2:1:1.