I keep losing track of the file where I have these steps written down. It’s past time to put them someplace where I can find them, and perhaps help a few others as well.
create database SOME_DATABASE;
create user 'SOME_USER'@'localhost' IDENTIFIED BY 'A_STRONG_PASSWORD';
GRANT ALL ON SOME_DATABASE.* TO 'SOME_USER'@'localhost';
The database permissions grant can be fine-tuned a bit, e.g. after installation, remove the DROP, ALTER, and GRANT permissions. (This does, of course, depend on what your plugins are doing, and potentially the needs of a particular major version upgrade.)