How can I troubleshoot MySQL error 1045 when connecting from a remote host?

First, verify the username and password are correct. Then, check if the user has permissions to connect from the remote host using `SELECT User, Host FROM mysql.user WHERE User='your_user'`. If the host is incorrect (e.g., 'localhost' instead of '%'), you need to grant the user access from the correct host using `GRANT ALL PRIVILEGES ON *.* TO 'your_user'@'remote_host' IDENTIFIED BY 'your_password'; FLUSH PRIVILEGES;`.