What is the Best Way to Get Cats Through Transtion After the Move?

We moved a couple of months ago and we also moved our cats' favourite spot, which is just a cardboard box. They spent the first few hours looking a bit nervous and always running back to their box if there was a noise they didn't recognize. It seemed really good for them to have a 'safe spot'.

The next day they seemed adjusted already, running and jumping around like it was our old home.