Let’s get focused.
I often see developers misusing CSS :focus styles because they either don’t find them useful or don’t like the way they look. I agree that the browser default focus styles aren’t the prettiest, but they don’t need to be. A focus style is a style used to clearly show that an element is focused. It should not be subtle. It should not be ‘clean’.
The Good
Take a look at the Uk Government’s website, and hit tab. 
Their links are set in a shade of blue, while their focus state introduce black text on a yellow-banner background. Perfectly legible.