I switched to diff-so-fancy as my git diff viewer a few days ago, and I love the way it handles whitespace changes, and generally looks nice. The pro-tips page has info on installing via zplug, which is cool and worth a look as well.

So, I now have pretty git diffs, but did you know that git diff works outside of repos? I didn’t, and it’s super handy! If you have two files, aa and bb, you can diff them with git diff aa bb – exactly as you’d use diff normally, except that it’ll use your configured diffing tool. Fancy!