Text sizing, font smoothing and box-sizing.  

The catch all `box-sizing: border-box;` eliminates a lot of headaches when using percentage based width and height calculations.
Credit: http://www.paulirish.com/2012/box-sizing-border-box-ftw/

The text size adjust properties prevent certain mobile browsers from automatically zooming fonts.
Font smoothing is a nice little addition to make fonts appear smoother in OS X.
Credit: http://jaydenseric.com/blog/forget-normalize-or-resets-lay-your-own-css-foundation