Make a list
It is always a good idea to make a list. That way you can make sure to be ready and organized during such a stressful time.
Have plenty of supplies
I recommend buying a little extra instead of having to make several trips to the store, most stores will allow you to return unused supplies.
Utilize wardrobe boxes
Wardrobe boxes are a great way to keep your hanging clothes from getting ruined.
Moving long distance
If moving long distance, make sure to keep out enough supplies for the trip, and also a good idea to keep them out of the way of the movers!
If you are doing the packing yourself, make sure to label the boxes good so the movers when unloading know exactly where things are gonna go. This makes things run alot smoother for everyone.