This question was posed to me years ago: when starting a new job, what three items should you bring? Keenly aware that first impressions last a potential lifetime, this is how I answered.

1. Something that shows confidence.
Bring your own coffee mug or a supply of pens. By starting your first day with "No thanks, I have my own," you demonstrate that you mean business.

2. Something that shows personality.
Bring a poster, a favorite book, CDs, or photograph. An immediately homey work space invites others to engage you in conversation.

3. Something that shows slight neurosis.
Supply your own toilet paper, keep a spare pair of socks or become fanatical about fresh breath. Definitely the trickiest of the three, this item catches your co-workers off guard and forces them to maintain some distance.