Know that swapping numbers and characters for letters doesn't help.
Another common belief is that substituting numbers or symbols for letters in words will make accounts more difficult to crack. Since attackers use sophisticated automated tools to hack accounts, the systems are able to swap potential characters. When password length is limited, rather than trying to use common words that use substitution, try to choose values that do not sound like words, or look like anything that would be found in a dictionary (t1i2m3e4 is not as strong as Gu83fv1Z). Another option is to create a sentence you will remember, then use the first letter of every word in the sentence. It is also good to keep up with common passwords being used so you stay away from those as well.