Inigo Quilez's full warping technique — domain warping and fBm combined. Both the warp displacement and the final flow angle are computed with layered noise:

p1 = p + warpStrength · fBm(p)
angle = fBm(p1) · 2π

The large-scale folding of domain warping gets the fine turbulent texture of fBm at every scale simultaneously. Sometimes a second warp layer is applied — warp the warped coordinates again — which pushes the folding into visceral, almost biological territory.

Key variables: warpStrength (low = textured fBm, high = dramatic folds), octaves (detail layers), warpLayers (1 or 2 — double warp appears ~40% of the time).