Have a Packing Plan
Before your moving day, determine whether you or the movers will be responsible for packing and unpacking your belongings. If you're doing the packing, make sure you use plenty of newspaper, bubble wrap or blankets for padding. This is important becasue if what you pack breaks during transport, the movers may not be held liable for it. Be sure to have enough boxes on hand and label them with your name, room destination and contents so it's easier to keep track of where it all needs to go in your new space.
Once everything's packed, try to sort the boxes by weight to make loading easier for the movers. Keep piles of boxes away from the doorways so everyone can easily walk around. Avoid piling stuff on heavy furniture that will get loaded into the van first.