I refactor the box every year because there are usually some new cables.

Some simple empirical rules:

• keep the shorter cables
• maximum of 3 cables of the same type: for donating, for lending, for spare
• USB cables that can transfer data > USB cables that don't transfer data
• no damaged cables
• store long cables as coils (tied up tight)
• store short cables in bunches (tied up tight)
• should be sorted and grouped into categories
• box should be sealed, but aired out once in a while (outgassing)