@runeranch things like "double sleeving" - I've stopped. Currently all my cards are stored in special wooden boxes that are perfectly made for it. In the original it was boxes for tea bags that had the exact width for Magic cards.
@papierzeit I've had bad experiences with boxes. Inner linings, top and bottom of some boxes. I mainly use binders for all my modern cards worth anything.
Wooden boxes sounds nice. Some your have done yourself?