The MacDoctor's previous post discussed 2-Step Verification in relation to online and specifically iCloud accounts. 2-Step is definitely the way forward and more and more online services are offering the provision all the time. As noted in that post, what's required is something you know and something you have. The something you know is usually a password. And something we here over and over again from clients is how difficult they find it to manage passwords, often leading to the worst of all possible worlds - the same password used across multiple sites. And while Apple's Keychain application provides some help, a more full featured solution is AgileBits 1Password.
This Mac, Windows, iOS and Android application not only stores an ever growing list of passwords but helps you generate and deploy strong passwords as required. You can sync the data across devices and additionally store commonly used Credit Card and secure information for daily use. The key is creating one strong password which you will then use to unlock and deploy all the myriad of passwords that you can create, with the help of 1Password, and never need to remember again.
The application isn't cheap and but money well spent to feel safe and secure online.