The Ikea Trones shoe cabinet stores shoes upright but they fall over if the cabinet isn't full. This divider prevents the shoes (or other tall items) from falling sideways in the cabinet. It clips to the back lip of the drawer and can be positioned anywhere along the drawer length. No adhesive or screws needed, just uses friction to stay in place.

I printed it in PLA with 0.12mm layer height and 20% infill.