Creating an FTP account is simple, log in to your Cpanel account, and under the "File" segment there is an FTP Account tab.
Click to proceed, You fill in a simple form of for login, domain, and password.
Login should be an email for the domain or subdomain you are creating FTP for. You simply type the email's first segment before "@" and select your domain and password to create.
Make your password always stronger which is better for security. You can change the FTP password where necessary.
The directory for the FTP will be automatically assigned (based on the domain or subdomain selected) unless you want to change it.
Note that you can create multiple FTP accounts on one cPanel user.