Make sure you have some refreshments and cash to tip. Aside from that, get out of their way because you won't help them. Stay busy (and out of the way) when moving companies are working. Whatever the specific reason you're using the services of a full-service moving company, it's a great idea to know what you're expected to do when the moving company packs and moves your things.
Ask people moving if they want water, coffee or other beverages and a light snack when they arrive. You'll also save time and help carriers if you disconnect lamps, kitchen appliances and anything else that needs electricity. It's critical to find the right balance when deciding what to do while moving companies move your things to create a stress-free environment. I agree with you when you say that the first thing you have to do is be prepared for when the moving company comes to your house.
At the same time, people who move don't expect (and this is what I've seen) rooms with floors half covered in garbage and dirt. It's important to check your credentials and make sure that the moving company you're considering moving to is licensed and insured. Try to keep fragile items together in one area and be sure to label all boxes that way, so that carriers know how to handle them delicately. Once the moving truck is loaded, make sure the carriers have the right address for your new place and give instructions on how to get there if necessary.
Make sure you're home when the moving company is about to finish its work, as you'll have your hands full during the last stages of the move. As movers clean each room, take a final tour of the space looking through the closets and behind the doors to make sure there's nothing left. As a customer, there are hundreds of things you can do to help the moving company; but keep in mind that none of them involve being a moving company. Someone needs to be present to answer any questions the carriers may have and perform the rest of the tasks listed then.
Designating a space that moving companies can leave alone can be as useful for the customer as it is for moving companies.
