Don't carry passengers. Passengers should not be transported until the new driver has a consistently safe driving record without traffic citations or driver-caused accidents. Passengers, to the new driver, represent a source of distraction and also of increased responsibility and liability. Don't drive after dark. Automatic reflexes and driving skills are just developing during those first few months of driving.
Darkness adds another element that can be confusing to a new driver.
Nighttime is also the most frequent time to find intoxicated drivers on the road. Accident-avoidance skills will not be as well developed in the new driver making it more difficult to correct for problems should the new driver encounter an intoxicated one. Know the effects of alcohol. Have rules and stick to them. For example, should the parents discover that the teenager has been driving following any alcohol consumption the parent may ask the state to suspend the license until the teenager is 18.