I have progressrd to the point that the night stands carcases are
assembled. I am putting in drawers on full extension soft close slides
and they will be inset. I added a couple of rails between the drawers
on each cabinet front and back. The rails have two functions. Number
one function is to close the gap between the drawers and the secondary
function during assembly is to properly and quickly provide an index for
the slides and the slide spacers to sit on.

The process of spacing the rails.
https://www.flickr.com/photos/lcb112...posted-public/

The back fit of the back drawer rails.
https://www.flickr.com/photos/lcb112...posted-public/

And the first use of screws on the project. You see one at the end of
each rail screwed into the back or front face frame.

https://www.flickr.com/photos/lcb112...posted-public/

And here you see my set up for attaching the top cross bracing that will
help support the heavy marble tops. This set up insured that the
supports remained even at the top of the cabinet and evenly spaced.

https://www.flickr.com/photos/lcb112...posted-public/

Here you will notice the slide spacers sitting on top of the drawer
divider rails. The spacers insure that the slides are flush with the
inside edge of the face frame stiles. They will be screwed in place
into the side's front, back, and center stiles. I used the actual
plywood for those spacers to determine where to cut the grooves in the
FF stiles. The distance between the groove to receive the cabinet sides
and the inside of the FF stile need to exactly match the spacer.

https://www.flickr.com/photos/lcb112...posted-public/

Thoughts or questions?