falling into patterns with your passwords, which could then be guessed
That's a bit pessimistic. For somebody to be able to guess a "pattern" of passwords, they would need to have at least some of those passwords in order to deduce the pattern. But if they can find a sequence of passwords -- then presumably, they could have have found an unchanging password too.
But being required to change a password frequently, or to use passwords that are more complicated than necessary, increases the probability of the user having to save it or write it down somewhere -- and that certainly increases the probability of it being found.
As suggested by others, password managers combined with randomly generated passwords, is a great way to survive the many "leaks" we seem to have these days.
Two links that can be of use:
Check if you have an account that has been compromised in a data breach: https://haveibeenpwned.com/
An interesting article: "The only secure password is the one you can’t remember": https://www.troyhunt.com/only-secure-password-is-one-you-cant/
I developed system for producing passwords:
1. It's reliable and easy , you will never use the same passwords twice.
2. It's secure , you do not have to write it anywhere, just keep it safe in your head.
3. It's simple, you can have well over 50 passwords, yet you will still remember them all.
1. Choose CORE of your password: something you will well remember, it may be made up word that make sense only to you, or some important place/person/time/etc. For best results make sure your CORE has 6-8 letters minimum. Use small letters.
2. pick 1 or 2 letters from your password and replace them with numbers (letter "O" - number "0", letter "E" - number "3", letter "A" - number "4", letter "I" - number "1" etc.).
3. For each account add prefix to the CORE:
- in capital letters;
- from first letters of the service you are creating the password for;
4. Connect prefix with Core with one of the "special signs" (!, @, ~, *, etc.).
1. I choose CORE word: futurama
2. I replace letters "A" for numbers "4", futur4m4
3. For GIFGAF account my prefix will be "GG" GGfutur4m4
4. I choose "~" for special sign GG~futur4m4
So my password for GiffGaff would be GG~futur4m4
My password for let say O2 would be O2~futur4m4
My password for BBC account would be BBC~futur4m4
for Gmail it would be GMAIL~futur4m4
for netflix N~futur4m4
Well you get the picture.
This way You don't need litter your head with all paswords, only the CORE and then just add your prefix. Isn't it fool proof?
REMEMBER: More secure services usually asking for passwords to be at least 8 signs long, consist of capital and small letters, at least one number and 1 special sign.