Skeletons
Blocks to a near-solved cube.
Block building and skeletons
The classic approach builds blocks, as Petrus and Heise do: a 2x2x2 block, extended to a 2x2x3, then the first two layers but a pair, solving pieces where they already are rather than in a fixed order. Stop when what is left is a few pieces that a commutator can cycle: that sequence is the skeleton.
What a good skeleton leaves: three corners cycled and everything else solved.
Checked by the engine: 3 corners moved, 0 edges moved, 0 centers moved
R2 B' L D2 [D, R U R'] D2 L' B R2