People who attempt to remember passwords generaly pick simple passwords & reuse them often. One of the best ways to improve the strength of your passwords is to use a password manager.
“People who are trying to break into online accounts don’t just sit down at a computer and make a few guesses… Computer programs let them make millions or billions of guesses in just a few hours… Users need to go beyond choosing passwords that are hard for a human to guess: Passwords need to be difficult for a computer to figure out.” – Carnegie Mellon University passwords research group.
“The average internet user has 19 different passwords. It’s easy to see why people write them down on sticky notes or just click the ‘I forgot my password’ link. Software can help! The job of password management software is to take care of generating and remembering unique, hard-to-crack passwords for each website and application.” – Elon University computer scientist Megan Squire.
Some of the options for password managers include LastPass, Keeper, & 1Password.
There are free options, with limited features, available at https://lastpass.com/misc_download2.php