Some woods can be sensitive consider waxing wood furniture before storing. When stacking furniture use blankets or towels between them to prevent scratching. Stand mattresses on end as well as with sofas this will give more storage space. Put plastic covers on them if possible for protection. Take bed frames apart and put any screws in a plastic bag and tape to frame.
Pictures and mirrors:
Use bubble wrap or foam to protect them your items. You can also buy special boxes for them.
Glass and china:
You can buy boxes designed for them with dividers. Also make sure to wrap each item individually with bubble wrap paper, or any other wrapping material.
Clothing, curtains, drapes:
Use plastic storage bins if possible. They are air tight and a great way to protect any of these items. You can also use wardrobe boxes to hang your clothes. If you are storing wool use cedar chips or mothballs to prevent moth damage.
If possible use original boxes or use any box. Wrap with bubble wrap or paper.
Books & magazines:
Pack in small moving boxes they are easier to move and will not weigh too much.
Do not store Combustibles i.e. Gas, paint, paint thinners etc. Also do not store perishables or food items.