Give each child a garbage bag and have them go through their drawers and pull out everything that doesn t fit, is in bad shape ir that they haven t worn because they don t like it. They then need to bring these bags to your central sort area. Mine is the garage, I set up a folding table in the middle to sort on. I have purchased office boxes from Office Max. I like the standard size because they stack neatly.
Every box gets a number on the end starting with one.
You can also use a letter and a number. All boxes with boys clothing could begin with the letter B followed by a number. For instance B1, B2, B3 etc. I write on a label and affix it to the end of the box, the end that will be showing. Whenever I need an item I look on my list and locate the box.