I put in a piece of 2x4 in the corner, flush with the bottom edge. All pieces were glued. The 2x4 was screwed in place in addition to the glue. I put a screw through the back & into the 2x4, & a screw through the 2x4 & into the side. That way, there won't be any screws showing on completion.
Now wait a minute. That's how I did it. But the 2X4 should probably be placed with the wide part against the back and up high rather than flush with the bottom of the shelf as I show it. See Uh Oh , my next page.
To attach the dividers, I marked off placement first, dividing the space equally. I glued the dividers in place, making sure they were straight.
After the glue set, I put screws through the back & into the divider. Be careful, you have to make sure the screw goes straight & into the center of the divider. It would be easy to miss the middle of the board & end up with a screw tip breaking the surface of a divider. You really need to predrill these holes, if you don't, the screw tightening will pull the divider out of place.
I had sone 1X4 laying around, & cut off 3 short pieces to add as braces for the dividers, again, I used glue & screws to hold them in place.