1)    Contact your insurance company beforehand and confirm that your belongings are covered while in storage.

2)    Confirm when the unit was last exterminated.  If not recently, set off some spray bombs to clear away any unwanted critters before moving in your belongings.

3)    When putting belongings into storage for an undetermined time, be sure to keep out important documents, i.e., tax information, passports, etc.

4)    Label all boxes, so you can retrieve items you may need and simplify move-in later.