1. Don't be afraid to create long passwords. It's better to write down secure passwords than try to memorize short ones. Keep passwords written by hand on paper which you can keep secure in your home office. Don't save unencrypted passwords on your computer or online.
2. Passwords should always contain uppercase, lowercase letters and numbers. If allowed, also consider using symbols such as ! or %.
3. A good way to generate long passwords are to select 2 or more unrelated words, connect them with numbers, randomly capitalize some letters and, finally, adding a special character. Example: We can combine giraffe and tennis into giRaffe43tEnnis24!