the Hive infograpgh (amongst others) always comes to mind; 18 characters long, upper, lower, numerical, special. estimate time to brute force 438tn years.
not OP but I only have to remember two 18 character passwords, my laptop and KeepassXC. I use all of OP's suggestions as well as mixing languages, one being an indigenous language that only about 20K people in the world know, together with a little leet speak. I haven't been breached since the early 2000's.
the Hive infograpgh (amongst others) always comes to mind; 18 characters long, upper, lower, numerical, special. estimate time to brute force 438tn years.