This is kind of in my wheelhouse.

As noted above, a box is not going to give you the protection a purpose-built piece of luggage is, so in addition to meeting dim specs, proper packing is the key to survival.

If this item is in its retail packaging, the manufacturer has probably done this for you with foam inserts and the like. If you are self packing, make sure the contents are not susceptible to shock, puncture, crushing or torsion, all of which it is likely to experience.

Furthermore, try to ensure the contents don't experience potential internal damage as a result of insufficient packing material, that is, don't have the contents rattling around in the box in empty space. A well packed box should feel solid and secure, with little interior movement.

Above all, don't expect white glove treatment. My rule of thumb: pack with the expectation that the box will fall from shoulder height onto concrete and survive. If you have qualms about that, you should repack.