I've moved a lot. My best advice is use uniform sized boxes for as much of your packing as possible. They will stack more efficiently and use less room in the truck.
Also, color code your boxes depending on what room it will go. You can use different color masking or duct tape, or different color markers to place a marking on each side of the box so that no matter how it is situated in a stack you can see that it is for a specific room when unloaded.
Red for bathroom
Green for kitchen
and so on.
Start packing early. You can go ahead and pack up items you do not need on a daily basis. Such as pictures on the wall, knick-knacks, off season clothing, etc.
Designate one box for OPEN IMMEDIATELY for things like whatever is on your nightstand, i.e. alarm clock and things like that. And I would include a set of sheets/bedding in that box.
Pack a suitcase for personal items you will need right away like if you were going to a hotel. Change of clothes, your toothbrush, hair dryer, shampoo, medications, vitamins etc.