Go to Microsoft Password checker website to check your password strength: https://www.microsoft.com/protect/yourself/password/checker.mspx
I recommend including the following in your password:
1. Uppercase letter
2. Lowercase letter
4. Special character (Example: ! @ # $ % ^ & ? *)
Make sure to avoid the following:
1. Using your name.
2. Information which can be obtained about you (Ex: Things you own or love).
3. Ascending/Descending letters or numbers.
4. Known English or other languages words.
5. Using passwords less than 8 characters.
6. Writing your password down.
7. Save in your PC as a document or setup your internet browser to remember it.
A good practice is to change your password once a month.