For creating a new user with all privileges (use only for troubleshooting), at mysql prompt type:

mysql -u root -p 
GRANT ALL PRIVILEGES ON *.* TO 'yourusername'@'localhost' IDENTIFIED BY 'yourpassword' WITH GRANT OPTION;

For creating a new user with fewer privileges (should work for most web applications) which can only use the database named “database1″, at mysql prompt type:

GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON database1.* TO 'yourusername'@'localhost' IDENTIFIED BY 'yourpassword';