I generally know what I want commits for before I start writing. While writing I make my first commit once I've got one file changed, then ammend it as I go.

I generally know what I want commits for before I start writing. While writing I make my first commit once I've got one file changed, then ammend it as I go. If I write a whole ton of code/don't plan well in advance, I can end up with a few changes on the go at the same time. I'll tend to reset all the commits at the end and interactively add lines to commits