Windows 8 - What all and how should I backup?

So last month my HD crashed and I lost almost everything I had. Now, I keep regular backups. I store everything on the cloud.

For my HD backup, I use an external hard drive and create a system image regularly:

However I want to know if that's all I need for the worst case scenario. Say my HD crashes or Windows is unable to boot or anything like that. What do I need to have and how do I create proper backups?