When setting up a server or group of servers for the first time you may find yourself wanting to create MySQL users without having to login to MySQL. It would make sense for the mysqladmin command to offer this functionality but it does not. Instead you can create the MySQL user with the mysql command as shown in the below example performed on a server running Ubuntu Linux 12.04 also known as Precise Pangolin.
I always forget specific MySQL syntax including creating a MySQL user and granting that user specific access only via localhost to a specific database. So when I install Zen Cart I always end up looking how to do this via the MySQL documentation. Below are simple instructions on how to create a MySQL database using mysqladmin, create a MySQL user, and grant permission to the created database to the created MySQL user.
If you have the resources (CPU + RAM) available on your server then its can be a great troubleshooting tool if you enable MySQL logging which includes server messages, SQL query logs, and slow query logs. If you do not have the resources I would suggest only enable minimal logging such as only server messages and the slow query log since enabling all queries to be written to a file can become expensive rather quickly. Below I discuss enabling three different types of MySQL logging, adding a MySQL configuration file to logrotate, and configuring root to run mysqladmin commands without having to type the password out each time.