Spring yard work got rained out, so I spent a little time in the shop.
After adding the last couple of slats to the back panel, I broke nown the carcase to prep and pre-finish the interior before final assembly. One last step before sanding was to add shelf pin holes.
Arranging the side panels like a book match ensures the holes are aligned properly. I used the T-square and a couple of setup blocks to mark them at 2" spacing, 1.5" from the edges. I just put a couple of holes above and below center of each cabinet space, to allow minor adjustment of a floating shelf in each compartment.
Blue tape, a brad-point bit, and a scrap block to set the Hole depth and keep it straight. All contribute to a clean hole.
Final touch is to lightly chamfer the edge of the hole. This counter-sink is intended for metal work. Mounted in an un-attached drill chuck, I just give it a couple turns by hand. Too much can make the shelf pin wobbly.