Amongst many tips I got from Ernesto Ramirez, I particularly liked this method of rough hollowing the plates. At first I thought that it was a rather fussy approach but, having tried it myself, I find that it is quite practical, it saves a little time and reduces  the risk of cutting too deep.
When hollowing the plate, the most common method that I have seen is to make gouge cuts all the way across, down one side of the arch and up the other.  The problem with this method is that on the up-cut there is not enough clearance for the gouge to maintain its cutting angle, so there is a tendency to dig in too far, leaving thin areas on the up-hill side of the plate.
Ernesto’s method is good for people using the type of holding jig shown below as the plate doesn’t need to be taken out of the jig to take thickness measurements.
Start by marking your target depths on the center line, at the middle of each bout.
Measure the depth of the cut from the central bar
Cutting the second side is quicker than cutting the first: you only need make a visual depth match.  Note the extra wood left at the bottom of the ffs and above the top corners, two areas that commonly get over-thinned.

The central “bass bar” is quickly removed, the plate  ready to be adressed with a thumbplane…..