We were a military family for many years, my son has moved house 5 times and he is 8 years old. 
You do get quite organised though! 
First step for me in advance is a good old sort out. What you want to keep, what you might want to sell or give to the charity shop. Work through room by room. Make sure everyone does this - otherwise the removal men pack without prejudice and you may find yourself paying for removal of boxes of oily cloths and empty WD40 tins because the shed has been overlooked at the last minute.
Next, if you are packing yourself or not, start boxing up items you can live without for a few weeks - bookshelves, DVD's and spare bedding can be packed. Label clearly so you can priorities these boxes last when you unpack.
If you have a spare room or dining room you can live without start packing these up, or as a storage area for the packed and labelled boxes.
On the last few days of packing you might want to pack intimate items personally! 
Label all essential boxes clearly. Label each room clearly too.
I tend to take the kettle, Teabags, sugar squash and sone cups etc in the car so that you can get a brew going at the other end!
Give yourself a day in your move or lease to deal with the empty house. If you can afford it - get in a cleaning team. If not, rope in some friends to Vax carpets, vacuum cobwebs etc.
Many hands make light work - ask friends/parents to have the kids so they don't get in the way of lifting and loading. Make sure they have a few favourite toys to hand as it may e unfamiliar and a little bit upsetting.
We used to make sure DS said goodbye to the house, and picked his room in the new one if possible as it helped him settle in.
When you move in you can usually ask the removal company to come back and collect the boxes and all the paper that you don't need. They can reuse and recycle it.
Finally - lists, lists and more lists! Utilities to contact. New doctors, dentists to register, post redirection . You can get some good apps to help organised your " to do " lists.