Box up everything that you can. Anything left not in boxes in a self-storage facility can get dusty.
Fill boxes to capacity. The contents in half-empty boxes can shift during transport or lifting. Corners and sides can collapse if there’s nothing to support them. Foam peanuts are handy for filling in the gaps in boxes.
Distribute the weight in packed boxes evenly. Make sure they are not too heavy for you and others who may be lifting them.
Wrap all fragile items and breakables such as dishes, glasses, ornaments, etc. separately. Pack these items tightly into strong or reinforced boxes, filling any gaps with paper or filler. Mark “Fragile” on any boxes containing breakable items.
Clearly label all boxes on more than one side so you can easily identify the contents.
Pack books flat to avoid damaging their spines.