Stacking your items in storage
If you have even placed your things in storage you will know the amount of space provided and the amount needed in order to get everything in the unit. But, if you are on a budget you will most likely want the smallest unit you can get.
Try to put the heaviest items in the back. I made the mistake before of placing a washer and dryer in front of everything then when I had to get something out from a box I had to climb on top of the heavy equipment to get to it.
Stack light boxes on top of the heavy ones. This might seem obvious but you can easily make the mistake on squashing your light boxes. Trust me.
Place boxes on top of the heavy furniture and equipment. This will make sure that you use all available space by stacking it as high as possible without making it unsafe or damaging other boxes by applying too much weight.
Breakables go in the front and on top. Make sure that they end up on a heavy box and not in the back where they cannot be reached easily in case the box falls over.
Use nice boxes. I am talking about moving boxes specifically for that purpose or those big thick ham boxes you would get from the meat department in your local grocery store. You can be assured that they are more sturdy than others and will not crush as easily.