We're constantly giving them their basic socialization, they get used to strange noises, strange objects, other animal species, new people, etc. In the result, all of them are very brave, they're not afraid of a single thing.
We also upgraded their playing corner with new things, just as a see-saw for puppies, balance pillows and loud toys. So by the time they get to their new home, none of these things will be new for them. We're giving them a huuuge self-confidence. :)
Check out the video below, you can see there how cool their playing ground is.