How to Create a Strong Password that is Easy to Remember
The password consists of three strings: the constant string, the domain string, the age string.
The constant string is a secret string that you memorize and use in all your passwords. It should contain at least one of each lowercase letter, uppercase letter, number, and symbol, because some web sites require this. An example constant would be: 0s@Ct
Decide on some one secret, personal, esoteric method for creating domain strings from the domain name, and remember which method you decided on, like you remembered your constant string. You will apply this method to the domain name to create a domain string; for example.com you could use `xmpl` (remove the vowels), or `eae` (remove the constants), or `aeelmpx` (alphabetize), or `ExAmPlE`, or `elpmaxe`, etc.
Decide on some one secret, personal, esoteric method for creating age strings from your current age, and remember which method you decided on, like you remembered your constant string and your domain string algorithm. You will apply this algorithm to your current age to create an age string; examples: your age expressed in hex, or with digits reversed, etc. Having this in your password forces you to change passwords once a year.
Whatever methods you use, make sure that your total password length is guaranteed to be at least 9 characters long, because some web sites require this. If your domain and age strings are short, increase the length of your constant string.
Order these three elements in whichever way you'll remember best.
Domain String: example.com -> elpmaxe
Age String: 36 -> TSix
By deciding on and remembering three pieces of information: a constant string, a domain-string algoritm, and an age-string algoritm, you can have a unique, unguessable password for every domain, that changes once a year.