Create User
Set the username and password
dscl . -passwd /Users/<username> <password>
Set the user's default shell
dscl . -create /Users/<username> UserShell /bin/bash
Set the user's display name
dscl . -create /Users/<username> RealName "Real Name"
Set the user's primary group
dscl . -create /Users/<username> PrimaryGroupID 1000
Set the user's home directory
dscl . -create /Users/<username> NFSHomeDirectory /Users/<username>
Promote user to local admin
dscl . -append /Groups/admin GroupMembership <username>
Set the user's ID
dscl . -create /Users/<username> UniqueID 510