Pick the drivetrain. Pick the problem you actually feel in the car. Then choose how brave, sensible, or gloriously unhinged you want the setup direction to be.
More diff lock usually means better straight-line traction, but less willingness to turn.
Softer springs or damping usually means better grip on rough stages, but a little less sharpness.
More rake often improves turn-in, but can cost some stability.
More rear toe-in usually calms the rear down. Excellent medicine when the car behaves like a caffeinated badger.