Prepare for the photo, making sure to wear clothing you normally wear, but that is not a work uniform. Be sure your face is visible and not covered by a hat or obstructed by sunglasses or headphones.
Check to see what businesses offer passport photo services locally, and decide which one you want to go to. Some branches of the U.S. Postal Service offer this service, as well as stores such as Walgreens, CVS and FedEx Kinko's. It usually costs $10 to $15 to get a passport photo taken.
Call ahead to make sure the business has someone available to take your passport photo. Typically, stores have someone available during regular business hours and the process takes only a matter of minutes.
Review the photo to make sure it meets federal requirements. Photos must be 2 inches by 2 inches, in color, have a white or off-white background, and have your face directly facing the camera with a neutral expression and eyes open.