A password should not be a common word and number combination, such as “Summer2009”, “vinter123” or “PassWord98”.
Do not rely on obvious substitutions, for example “H0use” isn’t a strong password just because you’ve replaced and o with a 0. That is still a bad obvious password.
Try to find a sentence that is easy for you to remember. For instance, “The first house I ever lived in was 613 Fake Street. Rent was $400 per month”. You can then turn in that sentence to a password by using the first letter of each word, your password would then become “TfhIeliw613FK. Rw$4pm.” This is a VERY strong password.