FedEx ships packages from all over the world to your doorstep. Typically, when you are not home to answer the door and accept a package your FedEx delivery person will leave the package on your doorstep at his discretion. If the package requires a signature and you are not home to provide it, there are a few options you can execute to have your package delivered without your presence.
Check to see if your package was shipped using Indirect Signature Release. If it was shipped this way you can leave a note on your door with your signature, the date and a short note instructing your FedEx delivery person to leave the package at your door.
Read the note on your door left by your FedEx delivery person if he is unable to leave your package at the door. The note will instruct you to either be home to sign for your package the following day or to pick it up at a specific FedEx location. If the door note states that you can sign the note and leave it for the delivery person you can do that and your package will be left the following day.
Ask a neighbor to sign for your package for you and leave a note on the door for your FedEx delivery person stating that you have given permission for your neighbor to sign for and accept the package.