I propose this custom-designed accessory drawer for the shelf I have in the garage where I have stored all my accessories for soldering electronic boards.
As printing material I used PLA and the supports are in Petg to ensure that the model is as clean as possible.

NB: I recommend making the fixing brackets with 5/6 walls so that they are sturdy to avoid cracks when the fixing screws are tightened too much.

There are two models of brackets, one is used for fixing to the side and the other for fixing under the shelf. If you fix everything under the shelf I recommend not printing the straight bracket and printing two large brackets.