Unlike personal accounts, access accounts can be shared, but are restricted by location. As with a personal account there is a four-tab wizard.
First you set the, password and expiry date. This is a shared account and might even have its details posted on a wall, so giving it a username and password that are easy to type is a common approach and quite OK (there is another limitation on the account).
These are the IP addresses where the account will work. You can use wildcards and hostnames for wider ranges, but you must list the external IP address - any starting with 10. or 192. are internal addresses and will not work. There are many online resources that will display your IP address for you.
The title of the account so you can easily tell access accounts apart. The department and address fields will inherit from your administrator account but can be changed.
Which permission sets should be assigned to the account. Default permission sets are already selected.