[colinbartlett]

I use git add --patch

My teammates probably get tired of hearing it, but every time someone erroneously commits some file or line I advocate its use.

[Estragon]

Magit in emacs is great for this functionality. It will even add just the selected region of the diff.

[JamesSwift]

I've defaulted to this for some time now, and have no issues with keeping my own smattering of me-specific configuration overrides. Plus, there are a couple other times when being able to work through the patching interface is a handy skill to have.