Conventional wisdom states that a good password should be difficult to figure out by hackers or people that know you. People often accomplish this by creating a password that mixes case, and substitutes letters with numbers and symbols. This really isn’t very helpful, and many people take to the habit of writing down their password and sticking it to their monitor, which defeats the purpose in having a secure password. So what should you do?
Now some Web sites force you to do some things. For instance, Twitter will not allow you to have a space in your password. Not that big of a deal, just don’t have a space between the words. For ones that require different cases and numbers/letters just upper case the first letter in every word and use a number/character instead of a space and/or end the password with some characters you’ll remember.