resize/rescale/recreate

WIP 64px icon (far right).

I am currently working on modifying 128px icons for the retina display (128px -- > -- 64px).

It got me thinking, how do others modify their icons, when the design already exists? Everyone is different, so too will their workflows be - what's your method*?

I recreate in the majority of cases, especially so with high detail icons, like in the preview - but sometimes, I rescale icons and modify the pixel lines. As I heavily use smart objects in my workflow, it can take more time to perfect rescales, as smart objects do not scale, the contents remain at 100%.

*There really is no right or wrong answer, but some may lead to a more attractive result :p