I went around the web, reading articles about business card mistakes, and here is a full list of them:

 1. Don't use cheap materials/techniques or attempt to print your own.
 2. Don't use metal business cards.  They won't get through airport security.  (Is that true?)
 3. Don't use a big font for the address and contact info. 
 4. Don't put a picture of your face on the card.
 5. Don't use pixelated or other substandard images.
 6. Don't flirt with the margins.
 7. Don't overcrowd your card.
 8. Not including information that is attractive to clients, i.e. "5-year warranty," etc.

Obviously name, address, email, phone number, and fax number are necessary, but are there any other do's or don't's?

PS: For a 3.5x2 card, I should use the following settings in Photoshop, correct?  3.75x2.25, 300 DPI.