Leather Cable Wraps and Cord Organisers
The cheapest thing here, and the one that most improves the inside of a bag.
Vegetable-tanned leather cable wraps that keep a charger, earphones or a laptop cable coiled instead of tangled through everything else. Made by hand in our own workshop from Leather Working Group gold-certified leather, tanned with natural tannins so they start pale and darken with handling.
There are three, and the product page says which cable each one suits.