• Set up a "read-only" user in addition to your administrative user and use that by default unless you actually need to make changes on production servers.

• Disable autocommit, or use explicit transactions so you can rollback mistakes. (Beware of implicit commits)

• To avoid UPDATE without WHERE you can enable sql_safe_updates. Some clients have similar options.

• Get into the habit of running a SELECT query before running an UPDATE to check which (and how many) records you've selected.

• Use color schemes to differentiate between hosts. Many terminal clients and SQL clients have the ability to set / change the color scheme.

• Changing the prompt (PS1 in bash, or the mysql cli prompt option)

• Minimize the need for accessing the production database directly:

  • Use migrations when making production database updates whenever possible (in addition to passing the queries through CI, this means you keep a record of what changes were made and when).
  • If there's things you commonly query, turn them into a "developer tool" page in your application (obviously with access restricted to developers).