The best is if you mix your passwords up daily or make a bot that auto scrambles your passwords to a new one every few hours so you don`t have to do it manually.
I think the easiest option for most newbies is to use a password manager such as KeePass. You only need to remember one complicated password, which is your encryption key to KeePass. KeePass will generate long and truly random passwords as often as needed for any site, and never duplicate passwords.
I second this. I personally use LastPass, but they are both really good password manager solutions.