You probably have a lot of accounts on the web, if you do not use secure passwords or have a good system you probably use the same password for several sites ?
This is a big problem, password managers are a possible solution, but that might make other problems if you want to login on another computer, or on your cell phone, I am not to fund of using password managers.
So I have a particular system for creating passwords for everything, and have them all in your head.
The thing about if you can recall your password it is not secure is pure bullshit if you have a proper way to make passwords or a good memory technique this is not a problem.
So let us say you have to make 5 passwords for the following sites
so now let us take whatever password you might use now (the following is completely random and not in any way my pw nor anybody elses that I know of)
that is a pretty decent base I think.
Creating the passwords
So Now let us create these passwords starting with the gmail one
see we take the base password and add the name of the website on at the end, this makes the password unique for every site and it makes it very easy to remember, also if you want it to be a bit stronger you can take this form
this makes it a whole lot harder to crack, the same structure is useful for all the websites.
Alternative form of creating passwords
This one I do not use as such, but it might be feasible to make a password that is a sentence
so let us take gmail again as an example of a website to make a password for
Gmail is my mail server H@msen28346720
Bold is to delimiter the password
Spaces are not acceptable everywhere, so perhaps it is better not to use them at all.
If you have a good setup for creating passwords or you like the password managers that is all fine, personally I just prefer to memorize it, then I can be sure to always have it with me.