What do your characters leave behind unintentionally? Can they get their possessions back? What happens to possessions being handed in? Is there a Lost Luggage Depot, for example? What habits (including losing keys!) aggravate your characters the most?
Are your characters the kind that are generally well organised or do they "wing it" from one crisis so the next one?
Your character will cause and be the cause of concerns for other characters so how does this aspect of their personalities show through and how to the rest of "your cast" respond to it?