The fitting of parts has got to be the most fun there is in fine cabinetmaking. I really mean it. Sharp tools, precise measurements, a little patience; and you're good to go! I should tell you that precise measurement doesn't mean I'm getting out the micrometer or even the measuring tape. No, all I need are a simple straightedge and a square. What I'm measuring or looking for when I apply the instrument to the wood, or when fitting together two pieces of wood, are gaps. Gaps can show up as thin dark lines if lit from in front or slivers of light if lit from behind. Eliminate the lines and photons, and the parts will be fitted and ready for final surface preparation.
There will be one drawer in each of the flanking cabinets of this entry hall mirror. When I constructed the carcasses I deliberately created drawer pockets that were ever-so-slightly wider in the rear than in the front. This imperceptibly subtle wedge shape does two things. First, it allows for precise fitting of the partitions and shims after the carcass is assembled. Second, it provides for a snug fit of the drawers when they are in their open position, offering a slight resistance, telling you when to stop.