One of the most time-consuming things in my Torres copy is the herringbone in the rosette. First you have to make it, ensure that all of the points come together and then be sure that the centreline conincides with the middle of the top. Unless you are willing to accept imperfect “arrowheads” the way this guitar-maker was (see the way the interior herringbone is completely shifted and asymmetric) or you are willing to throw a lot of strips away after glue-up then you are stuck with doing it the only way that guarantees results:  one strip at a time.  The trick is to work with your final rosette depth (say 2mm), cut off a strip, flip it and then glue it back on to the larger piece after lining it up perfectly.  Then you cut it off again and thickness it to the point where both sides are equal.

Now prior to this you have to glue up alternating veneers and then cut them at an angle to get the half herringbone stock in the first place.  Some lutherie texts suggest you work with full height like what you see in the last photo and then slice off the full herringbone strips but I can guarantee you that your points will not all line up.   Actually, having a thin white strip in the middle allows for a bit of imperfection because it is not quite so visible.