"CAUTION: several people I know, including guys very proficient in Git, have complained about "git ate two days worth of my work!". It is easy to make errors in rebasing and reset --hard, and you may end up losing commits."

Like everything else in git, the solution to this problem is just to make more branches.

If you're about to do something like a rebase, just fork off a new branch first. It makes it trivially easy to get back where you started if something goes wrong. That's the whole point of version control, after all.