Follow the simple steps in the order mentioned below to have your USB drive mounted on your Raspberry Pi every time you boot it.
These steps are required especially if your are setting up a Samba share, or a 24x7 torrent downloader, or alike where your Raspberry Pi must have your external storage already mounted and ready for access by the services / daemons.
Step 0. Plug in your USB HDD / Drive to Raspberry Pi If you are using a NTFS formatted drive, install the following