Double check around your house, with family members and neighbors. If nothing is found then, please call the carrier and give them your tracking info and let them know you never received it. They normally put a trace on it and 95% of the time, they end up finding it.
NOTE: Fedex SMARTPOST customers – call your local Post office. (Let them know it is Fedex Smartpost as they have to add a 92 to the beginning of your tracking number to find it).
IF it's still missing, then Contact Us via email or phone anytime.