all very good suggestions.

Another simple solution would be to have a system that is always the same:

@word%!%2315184@

as in: symbol - word - symbols - number corresponding to the word used in part one - symbol.

Or some such thing. By using the same word/numeric representation of word, you are quite likely to remember the password.

I had a period of using phrases that are always remembered together with an ampersand:
frankie&johnny, macaroni&cheese, bonny&clyde, hugz&kisz adding symbols and things.

I also had a mathematical period where I used squares and cubes together with words.

So a password might well look like this:
&&7sq49!magnesIUm&&
and then I could just change the number to square use a different element for the second part - systematic, yet difficult to hack.