Couple of days back my TeraByte HDD crashed and I lost almost everything, including my homedir. I will tell you my experiences and how my measures helped me lose not much data. So I will begin with one of the most important aspects. My BROWSER.
I have all my passwords stored in the browser and I rely on them so it is not stored anywhere else. Also, I have lot of bookmarks which help me do lot of stuff. Meaning, all these are very important for me. So, I had a backup plan for my passwords and bookmarks.
It allows you to save your bookmarks on their site or on your own URL.
If you have your own domain and you have a hosting provider, like I do, then you can configure Xmarks to save the bookmarks and the passwords on your domain. So, I downloaded this addon as soon as I could get my hands on a working system and installed this extension, configured Xmarks and was back will all passwords and bookmarks. Great to be up and running so fast.
BTW, I am yet to get a replacement for my HDD, working on Live Distro till then.