I choose the point on the cushion nose that's "equal angle" to the target (whether at a sight or between them), then visualize a line running perpendicular across the rail at that point from cushion nose to the outer edge and choose a point on that line that I've learned works for how steep or...
The “technical” definition is rarely exactly what’s needed - only when the cue’s pivot length is exactly at the grip hand and there’s no swerve. Since the shaft’s actual pivot length is almost never right at the “front” or “back” hand we’re almost always making subconscious microadjustments...